Conductive polymer materials and applications thereof including monitoring and providing effective therapy

ABSTRACT

Conductive materials and devices, apparatuses, systems and methods that employ same. The conductive material can include a conductive polymer material that can be utilized to monitor one or a combination of conditions during patient therapy, such as patient access, solution compounding and the like. This can facilitate the safe and effective administration of patient therapy, such as dialysis therapy.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 10/121,006 filed on Apr. 10, 2002.

BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to conductive polymermaterials and methods of preparing and employing same. Morespecifically, the present invention relates to conductive polymermaterials and applications thereof including monitoring patient accessdisconnection, monitoring solution mixing and compounding and the likeduring medical therapy, such as dialysis therapy.

[0003] A variety of different medical treatments relate to the deliveryof fluid to and/or from a patient, such as the delivery of blood betweena patient and an extracorporeal system connected to the patient via aneedle or needles or any suitable access device inserted within thepatient. For example, hemodialysis, hemofiltration and hemodiafiltrationare all treatments that remove waste, toxins and excess water directlyfrom the patient's blood. During these treatments, the patient isconnected to an extracoporeal machine, and the patient's blood is pumpedthrough the machine. Waste, toxins and excess water are removed from thepatient's blood, and the blood is infused back into the patient. Needlesor other suitable access devices are inserted into the patient'svascular access in order to transfer the patient's blood to and from theextracoporeal machine. Traditional hemodialysis, hemofiltration andhemodiafiltration treatments can last several hours and are generallyperformed in a treatment center about three to four times per week.

[0004] During any of these hemo treatments, dislodgment of the accessdevice can occur, such as dislodgment of a needle inserted into thepatient's vascular access including an arterio-venous graft or fistula.If not detected immediately, this can produce a significant amount ofblood loss to the patient. The risks associated with a needledislodgment are considerable. In this regard, important criteria formonitoring blood loss include, for example, the sensitivity, specificityand response time with respect to the detection of needle dislodgment.With increased levels of sensitivity, specificity, and response time,the detection of needle dislodgment can be enhanced, and blood loss dueto dislodgment can be minimized.

[0005] Typically, patients undergoing medical treatment, such ashemodialysis, hemofiltration or hemodiafiltration, are visuallymonitored in order to detect needle dislodgment. However, the needle maynot be in plain view of the patient or medical staff (i.e., it may becovered by a blanket) such that it could delay detection and, thus,responsive actions to be taken in view of dislodgment, such as stoppingthe blood pump of the extracorporeal machine to minimize blood loss tothe patient.

[0006] Moreover, in view of the increased quality of life, observedreductions in both morbidity and mortality and lower costs thanin-center treatments, a renewed interest has arisen for self care andhome hemo therapies. Such home hemo therapies (whether hemodialysis,hemofiltration or hemodiafiltration) allow for both nocturnal as well asdaily treatments. During these self care and home hemo sessions,especially during a nocturnal home hemo session, when the patient isasleep, dislodgment risks are more significant because nurses or otherattendants are not present to detect the dislodgment.

[0007] Although devices that employ a variety of different sensors areavailable and known for detecting and/or monitoring a variety ofdifferent bodily fluids, these devices may not be suitably adapted todetect needle dislodgment. For example, known devices that employsensors including pH, temperature and conductivity have been utilized todetect bedwetting and diaper wetness. Further, devices that employpressure sensors and/or flow sensing devices are known and used duringmedical treatment, such as dialysis therapy, to monitor fluid flowincluding blood flow to and/or from the patient. However, these types ofdetection devices may not provide an adequate level of sensitivity andresponsiveness if applied to detecting blood loss from the patient dueto needle dislodgment. Although venous pressure is known to be used tomonitor needle dislodgment, it is not very sensitive to needle drop-out.

[0008] Additional other devices and methods are generally known tomonitor vascular access based on the electrical conductivity of blood.For example, Australian Patent No. 730,338 based on PCT Publication No.WO 99/12588 employs an electrical circuit which includes two pointsthrough which current is induced in blood flowing through anextracorporeal circuit in a closed loop. Electrical current is inducedby means of a coil that is placed around the outside of the tubing ofthe blood circuit. Thus, each coil does not directly contact the bloodas it circulates through the tubing. In this regard, an electricalcurrent is induced in the blood loop by an alternating current thatflows through one of the coils. The second coil is then utilized tomeasure a change in amperage of the induced current as it flows throughthe blood circuit.

[0009] In this regard, electrical current is coupled to a bloodtreatment system that includes a number of high impedance components,such a blood pump, air bubble traps, pinch clamps and/or the like.Because of the large impedance of the conducting fluid loop (due to theperistaltic pump and other components), the induction and detection of apatient-safe current requires an impractically complex design of thecoil and system. Further, a high level of noise would necessarily resultfrom the use of such levels of induced current. This can adverselyimpact the sensitivity of detection. If lower currents are used, thefield coil would have to be increased in size to detect such low currentlevels. This may not be practical in use, particularly as applied duringdialysis therapy.

[0010] PCT Publication No. WO 01/47581 discloses a method and device formonitoring access to the cardiovascular system of a patient. The accessmonitoring employs an electrical circuit which can generate and detect acurrent at separate points along a blood circuit connected to thepatient. Electrical current is coupled to the blood using capacitivecouplers that each have a metal tube placed around the blood circuittubing. In this regard, the metal tube defines a first plate of acapacitor; the blood circuit tubing defines the dielectric; and theblood inside of the blood circuit tubing defines the second plate of thecapacitor.

[0011] The generator applies a potential difference between a pair ofpoints to generate a current in a segment of the blood circuit. Adetector utilizes an additional and separate pair of contact points tomeasure the current along at least one section of the venous branchbetween a first contact point and the venous needle. The change involtage (dV) can then be determined based on a measured change incurrent and compared to a reference range (I) to monitor accessconditions. In this regard, PCT Publication No. WO 01/47581 requires acomplex circuit design that utilizes multiple sets of capacitivecouplers to monitor vascular access conditions. This can increase thecost and expense of using same.

[0012] Further, the mere use of capacitive coupling to inject anelectric signal in the blood circuit and/or for detection purposes canbe problematic. In this regard, the signal must pass through the tubingof the blood circuit as the tubing acts as a dielectric of thecapacitor. This may cause an excess level of noise and/or otherinterference with respect to the detection of changes in vascular accessconditions.

[0013] In this regard, it is believed that known devices, apparatuses,systems, and/or methods that can be used to monitor a patient's accessconditions may not be capable of detecting change in access conditions,such as in response to needle drop-out, with sufficient sensitivity andspecificity to ensure immediate detection of blood loss such thatresponsive measures can be taken to minimize blood loss. As applied, iftwenty seconds or more of time elapses before blood loss due to, forexample, dislodgment of the venous needle, over 100 milliliters in bloodloss can occur at a blood flow rate of 400 ml/min, which is typical ofdialysis therapy. Thus, the capability to respond quickly upon immediatedetection of dislodgment of an access device, such as a needle, from apatient is essential to ensure patient safety.

[0014] In addition to dislodgement, additional other parameters are, ingeneral, monitored to evaluate changes thereof during medical proceduresincluding dialysis therapy. For example, temperature sensors, pressuresensors, conductivity sensors and the like are generally known and usedin a variety of ways to detect and monitor condition changes duringmedical therapy.

[0015] As applied to dialysis therapy and the like, a dialysis solutioncan be administered to a patient in mixed form. In this regard, theextent to which the solution is mixed can have an impact on theeffectiveness of the associated therapy. In dialysis therapy, thesolutions may have varying pH levels that are at levels considered to benon-physiologic prior to mixing, while after mixing, the final solutionis required to have a pH at a physiological level necessary foreffective and safe administration during therapy. In general,conductivity sensors and pH sensors are known and used. However, it isbelieved that known sensors may not be as effective in terms ofdetection capabilities and relative ease of use, particularly as appliedduring dialysis therapy.

[0016] Accordingly, efforts have been directed at designing apparatuses,devices, systems and methods for improved monitoring of patient therapy,such as detecting changes in patient access conditions in response toneedle dislodgment, detecting changes in solution compounding andmixing, and the like, wherein detection is sensitive, specific andimmediate in response to such changes such that responsive measures canbe suitably taken to provide the patient with effective therapy, such asdialysis.

SUMMARY OF THE INVENTION

[0017] The present invention provides improved devices, apparatuses,systems and methods that utilize electrically conductive materials tomonitor a variety of different conditions or parameter changesassociated with the administration of one or more solutions duringmedical therapy. In turn, this can facilitate the safe and effectiveadministration of the medical therapy, such as dialysis therapy.

[0018] In an embodiment, the conductive material includes a polymerconductive material that can include, for example, a polymer conductivecomponent or a polymer matrix and a separate conductive component thatis incorporated within the polymer matrix. The conductive materials ofthe present invention can be utilized in a number of differentapplications. For example, the conductive materials, such as theconductive polymer material, can be employed to monitor solution mixingand compounding. This can be utilized to evaluate whether the solutionor solutions have been effectively mixed prior to administration duringtherapy. This can be determined by monitoring a pH change in thesolution based on changes in conductivity. In this regard, the solutioncan be derived from a mixture of solution components with varying pHlevels, such as between about 1.8 to about 9.2. Thus, the presentinvention can be utilized to determine whether the pH of the mixedsolution is effectively maintained prior to use.

[0019] The present invention provides improved devices, apparatuses,systems, and methods for detecting dislodgment or disconnection of anaccess device, such as dislodgment of a needle inserted in a patientduring dialysis therapy. The devices, apparatuses, systems, and methodsof the present invention utilize an electrical circuit with a number ofelectrical contacts which are in fluid contact with the fluid circuitsuch that an electrical signal can be injected into at least a segmentincluding, for example, a loop defined along at least a portion of theconducting fluid circuit. In this regard, a direct-contact measurementcan be used to provide immediate detection of a change in an electricalvalue in response to a change in access conditions, such as a change inimpedance due to dislodgment of a needle or other access device from thepatient during medical therapy including, for example, dialysis therapyand medication delivery.

[0020] An advantage of the present invention is to provide an improveddevice, apparatus, system and/or method for monitoring patient therapy,such as for detecting patient access disconnection, for monitoringsolution compounding and the like.

[0021] Another advantage is to provide devices, apparatuses, systems andmethods that employ electrically conductive materials, such asconductive polymer materials, to monitor patient therapy, such asdialysis.

[0022] A further advantage of the present invention is to provide animproved device, apparatus, system and/or method for detectingdislodgment of an access device from a patient during medical therapyincluding dialysis therapy.

[0023] Yet another advantage of the present invention is to provide asensitive, specific and responsive apparatus and/or device formonitoring patient therapy, such as for detecting access disconnectionduring selfcare and home hemo treatments and for monitoring solutionmixing conditions, such as pH changes, prior to use.

[0024] Moreover, an advantage of the present invention is to provide aviable device or apparatus for allowing a patient or other non-medicalpersonnel in a non-medical facility to administer a dialysis therapythat uses a portion of the patient's circulatory system.

[0025] Furthermore, an advantage of the present invention is to providean improved device, system and method for monitoring and/or controllingblood loss from a patient.

[0026] Yet another advantage of the present invention is an improveddevice for connecting an electrical contact to a fluid circuit allowingfluid and electrical communication between the electrical contact andfluid flowing through the fluid circuit.

[0027] Yet a further advantage of the present invention is to facilitatethe safe and effective administration of medical therapy, such asdialysis therapy.

[0028] Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention and the figures.

BRIEF DESCRIPTION OF THE FIGURES

[0029]FIG. 1A illustrates a schematic view of an embodiment of thepresent invention showing two needles insertable within a patientthrough which blood flows to and from an extracorporeal system.

[0030]FIG. 1B illustrates a schematic view of an embodiment of thepresent invention capable of detecting needle dislodgment duringdialysis therapy.

[0031]FIG. 1C illustrates a perspective view of an embodiment of thepresent invention showing access disconnection detection capabilitiesduring medical therapies administered via a single needle.

[0032]FIG. 2A illustrates an exploded view of an electrical contactcoupling device in an embodiment of the present invention.

[0033]FIG. 2B illustrates a side sectional view of the coupling deviceof FIG. 2A in an embodiment of the present invention.

[0034]FIG. 2C illustrates another embodiment of the coupling device ofthe present invention.

[0035]FIG. 2D illustrates another embodiment of the coupling device ofthe present invention showing a threaded engagement between thecomponents of same.

[0036]FIG. 2E illustrates a sectional view of FIG. 2D.

[0037]FIG. 3 schematically illustrates an embodiment of the presentinvention relating to processing of a measurable voltage signal tocorrect for changes in baseline impedance during treatment.

[0038]FIG. 4A schematically illustrates a hemodialysis machine in anembodiment of the present invention.

[0039]FIG. 4B schematically illustrates a hemodialysis machine coupledto a patient's access via a tubing set in an embodiment of the presentinvention.

[0040]FIGS. 5A and 5B illustrate a coupler according to an embodiment ofthe present invention.

[0041]FIG. 6 illustrates a dialyzer according to an embodiment of thepresent invention.

[0042]FIGS. 7A and 7B illustrate a sensor assembly according to anembodiment of the present invention.

[0043]FIGS. 8A and 8B illustrate a single-piece sensor according to anembodiment of the present invention.

[0044]FIG. 9 illustrates a multi-chamber bag according to an embodimentof the present invention.

[0045]FIG. 10 illustrates a multi-chamber bag with a peelable sealaccording to an embodiment of the present invention.

[0046]FIG. 11 illustrates an automated peritoneal dialysis systemaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0047] The present invention generally relates to electricallyconductive materials that can be effectively employed to monitor patienttherapy. This can facilitate the safe and effective administration ofpatient therapy, such as dialysis therapy. In an embodiment, theconductive materials of the present invention include a conductivepolymer material as described below in greater detail.

[0048] The present invention provides medical devices, apparatuses,systems and methods for detecting access disconnection. Morespecifically, the present invention provides medical devices,apparatuses, systems, and methods that employ, in part, an electricalcircuit with electrical contacts in fluid contact and electricalcommunication with a fluid circuit allowing a direct conductivitymeasurement to be used such that dislodgment of a needle or other accessdevice through which fluid flows between a patient and the fluid circuitcan be immediately detected. In this regard, fluid loss (i.e., bloodloss) due to, for example, dislodgment of a needle from a patientundergoing medical treatment, such as dialysis therapy, medicationdelivery or the like, can be controllably minimized. In an embodiment,the conductive polymer materials of the present invention can beutilized to monitor solution compounding and mixing to ensure effectiveadministration of the mixed solution during therapy, such as todetermine whether a pH level of the mixed solution is effectivelymaintained prior to use.

[0049] It should be appreciated that the present invention is notlimited to the detection of needle dislodgment but can be utilized todetect the dislodgment or disconnection of any suitable access device.As used herein, the term “access disconnection” or other like termsmeans any suitable condition or event which can cause a loss or leak ofan electrically conductive fluid flowing along a fluid circuit connectedto the patient provided that a change in the electrical continuitybetween electrical contacts coupled to the fluid circuit can bedetected. It should be appreciated that a change in the electricalcontinuity as measured by an electrical value, such as impedance, may bedetected even in the absence of dislodgment of an access device from thepatient. The term “access device” as used herein or other like termsmeans a suitable device that can be inserted within a patient such thatfluid, including blood, can pass to, through and/or from the patient viathe access device. The access device can include a variety of differentand suitable shapes, sizes and material make-up. Examples of an accessdevice includes needles, catheters, cannulas or the like. The accessdevice can be composed of any suitable material including, for example,stainless steel, plastic or like biocompatible materials.

[0050] Although in the embodiment set forth below the apparatus and/ordevice is designed for use in a dialysis therapy, such as hemodialysis,hemofiltration or hemodiafiltration, it should be noted that the presentinvention can be used in a number of different medical therapies thatemploy a variety of different and suitable fluid systems, such asextracorporeal blood systems. For example, the invention of the presentapplication can be used during intravenous infusion that can employ theuse of a single needle insertable within the patient for delivering amedical solution or drug, blood, blood products, processed blood or thelike between the patient and the fluid system. In addition, the presentinvention can be used in plasma exchange therapies, where a membrane isused to separate whole blood into plasma and cellular components.

[0051] With respect to dialysis therapy, the present invention can beused in a variety of different therapies to treat kidney failure.Dialysis therapy as the term or like terms are used throughout the textis meant to include and encompass any and all forms of therapies thatutilize the patient's blood to remove waste, toxins and excess waterfrom the patient. Such therapies include both intermittent, includinghemodialysis, hemofiltration and hemodiafiltration, and continuoustherapies used for continuous renal replacement therapy (CRRT). Thesecontinuous therapies include slow continuous ultrafiltration (SCUF),continuous veno-venous hemofiltration (CVVH), continuousveno-hemodialysis (CVVHD), and continuous veno-venous hemodiafiltration(CVVHDF). Dialysis therapy can also include peritoneal dialysis, such acontinuous ambulatory peritoneal dialysis, automated peritoneal dialysisand continuous flow peritoneal dialysis. Further, although the presentinvention, in an embodiment, can be utilized in methods providing adialysis therapy for patients having chronic kidney failure or disease,it should be appreciated that the present invention can be used foracute dialysis needs, for example, in an emergency room setting. Lastly,as one of skill in the art appreciates, the intermittent forms oftherapy (i.e., hemofiltration, hemodialysis and hemodiafiltration) maybe used in the in center, self/limited care as well as the homesettings.

[0052] In an embodiment, the present invention includes an electricalcircuit with a number of electrical contacts, preferably a pair ofelectrical contacts, in fluid contact and electrical communication withthe fluid circuit. The electrical contacts can include any suitabledevice through which electrical connection can be made with the fluidcircuit thereby defining a conductive pathway or conductor loop therein.In an embodiment, at least one of the electrical contacts includes aconductive polymer material as described below in greater detail.Changes in an electrical value or any suitable parameter associated withthe conductor loop can then be monitored in response to changes inaccess conditions as described below. In an embodiment, the electricalcontact includes an electrode which can be coupled to the fluid circuitsuch that an electrical connection can be made in fluid contact withfluid flowing through the fluid circuit as discussed below.

[0053] For example, a constant current or other suitable electricalsignal can be injected into the fluid circuit via an electrode pair incontact with the fluid flowing in between the electrodes therebydefining a loop along at least a portion of the conducting fluidcircuit. A change in an electrical value, preferably impedance, can thenbe measured in response to access disconnection. This can provide adirect conductivity measurement capable of detecting a change inimpedance or other suitable electrical parameter of the fluid, such asan electrically conductive fluid including blood, medical solutions orthe like, as it flows between a patient and a fluid system (i.e., anextracorporeal blood system) via a needle, needles or other accessdevice(s) inserted within the patient.

[0054] In this regard, the present invention can effectively detectdislodgment of a needle (e.g., a venous needle and/or an arterialneedle) or other access device through which blood or other suitablefluid can flow, for example, to, through, and from the patient, such asa blood circuit used during dialysis therapy. The detection capabilityof the present invention is believed to be immediate based on themeasurable change in, for example, impedance of the electricallyconductive fluid or fluids due to fluid loss resulting fromdisconnection of the access device from the patient.

[0055] The immediate detection capabilities of the present invention areimportant, particularly as applied to dialysis therapy where asignificant amount of blood loss can occur within a relatively shortperiod of time if delays in detection and responsive actions to stop theblood loss occur. Under typical dialysis conditions, if 20 seconds ormore time elapses before blood loss due to dislodgrnent is detected andstopped, over 100 milliliters of blood can be lost based on typicalblood flow rates of 400 milliliters/minute.

[0056] Applicants have discovered that the present invention can detectaccess disconnection, particularly in response to venous needledislodgment during dialysis therapy, with a high degree of sensitivityand specificity in addition to its immediate detection capabilities. Thedirect-contact measurement of the present invention is capable ofdetecting a change of an electrical value, preferably impedance, due toneedle dislodgment or the like as the blood flows through the bloodcircuit during dialysis therapy. As used herein, the term “electricalvalue” or other like terms means any suitable electrical parameter suchas, impedance, resistance, voltage, current, rates of change thereof andcombinations thereof. The detection of a change in impedance or the likeis an indication that the needle has become dislodged or other likecondition has occurred. It is noted that the detection capabilities ofthe present invention can also effectively detect blood loss duringmedical therapy resulting from a disconnection in the fluid circuit,even if the needle or needles have not become dislodged. In this regard,the present invention can be effectively utilized to controllablyminimize blood loss from the patient based on the ability of the presentinvention to immediately measure a change in impedance or the like dueto blood loss with a high degree of sensitivity and specificity. Thiscan facilitate the safe and effective administration of patient therapyas previously discussed.

[0057] The devices and apparatuses of the present invention can includea variety of different components and configurations depending on theapplied medical therapy such that fluid loss, particularly blood lossdue to needle dislodgment or the like, can be effectively monitored.

Multiple Access Disconnection

[0058] Referring now to FIG. 1A, an embodiment of the apparatus 10 ofthe present invention includes a pair of electrical contacts 12 in fluidcontact with a blood tubing set 14 of a blood circuit 16. The bloodcircuit 16 connects a patient 18 to an extracorporeal blood system 20 asapplied to, for example, dialysis therapy including hemodialysis,hemofiltration, hemodiafiltration, continuous renal replacement or thelike or plasma therapies. The pair of electrical contacts 12 includes afirst electrical contact 22 and a second electrical contact 24 which areattached to a respective first tube member 26 and second tube member 28of the blood circuit 16. The first tube member 26 is connected to avenous needle or other suitable access device inserted into a vascularaccess region (not shown) of the patient. The second tube member 28 isconnected to an arterial needle or the like also inserted into avascular access region (not shown) of the patient. During dialysistherapy, for example, blood flows from the patient 18 through thearterial needle to the extracorporeal blood system 20 that includes, forexample, a dialysis machine, via the second tube member 28 where theblood is treated and delivered to the patient 18 through the venousneedle via the first tube member 26.

[0059] As the blood flows through the blood circuit during dialysistherapy, a constant electric current or the like generated by acontroller 29 can be injected or passed into the flowing blood via theelectrical contact pair, preferably an electrode pair as describedbelow. In an embodiment, at least one additional electrode can also beutilized in any suitable manner.

[0060] The electrode pair connected to the controller 29 or othersuitable electronic device can then be used to measure a voltage changeacross an unknown fluid (e.g., blood) impedance or other like electricalvalue to detect a change in impedance or the like across the vascularaccess region. In an embodiment, one electrode can be used to inject theelectrical signal into the fluid circuit while the other electrode ofthe pair can be used to sense a change in the electrical value and passan electrical signal indicative of the same to the controller forprocessing and detection purposes. Upon dislodgment of at least one ofthe venous needle and arterial needle from the blood circuit or othersuitable condition, an immediate and detectable increase in impedance orthe like can be measured as compared to the impedance or other suitableparameter measured under normal operating conditions.

[0061] It should be appreciated that the present invention as embodiedin FIG. 1A can be modified in a variety of suitable ways depending onthe medical therapy as applied. For example, the venous and arterialneedles can be inserted into the vascular access of the patient on anysuitable part of the patient's body, such as the upper arm, lower arm,upper thigh area or the like during dialysis therapy. As previouslydiscussed, the present invention can be applied to a variety ofdifferent medical therapies including intravenous infusions, plasmaexchanges, medication delivery, drug delivery, blood delivery anddialysis therapies (i.e., hemofiltration, hemodialysis,hemodiafiltration and continuous renal replacement).

[0062] As illustrated in FIG. 1B, an embodiment of an apparatus 30 ofthe present invention is shown as applied during dialysis therapy. In anembodiment, the present invention includes a venous needle 32 andarterial needle 34 inserted within a patient access 36. The venousneedle 32 and arterial needle 34 are connected to the dialysis system 35via a number of tube members 38 that connect the various components ofthe dialysis system 35 including, for example, a venous drip chamber 40,a dialyzer 42, an arterial drip chamber 44 and a blood pump 46. Itshould be appreciated that one or more of the components of the dialysissystem can be provided within a dialysis machine coupled to the bloodcircuit. As shown in FIG. 1B, a first electrical contact coupling device48 and a second electrical contact coupling device 50 are positionedbetween the dialysis system 35 and the venous needle 32 and the arterialneedle 34. As used herein, the term “electrical contact couplingdevice,” “coupling device” or other like terms means any suitable devicethat can be used to connect an electrical contact to the fluid circuit.In an embodiment, the electrical contact coupling device can be used tocontact the electric contact to the fluid circuit allowing fluid contactand electrical connection with the fluid flowing through the fluidcircuit as described below.

[0063] In an embodiment, the electrical contact pair, preferably anelectrode pair, is connected to a controller 52 or other suitableelectronic device. The controller can be used to inject an electricsignal via the electrode pair and into the blood and/or other fluid asit flows through the blood circuit. This provides a conductor loop alongwhich changes in electrical parameters or values can be measured. Thecontroller 52 which is coupled to the electrode pair can also be used tomeasure this change. It should be appreciated that the controller caninclude a single electronic device or any suitable number of devices inelectrical connection with the electrical contacts to input anelectrical signal into the blood circuit thereby defining a conductorloop, to measure a change in an electrical parameter or value associatedwith the conductor loop and/or perform any other suitable tasks, such asprocessing the detectable signal as discussed below.

[0064] Preferably, the electrical signal is generated from a constantcurrent that is supplied to the electrodes until dislodgment occurs. Thevoltage across an unknown impedance of the fluid (e.g., blood)circulating through the blood circuit can then be measured (not shown)to detect a change in impedance due to changes in access conditions.However, it should be appreciated that any suitable electrical parameterand changes thereof can be monitored to detect needle drop-out or thelike as previously discussed.

[0065] As demonstrated below, the detection capabilities of the presentinvention are highly sensitive, specific and virtually immediate inresponse to access disconnection, such as needle dislodgment. Further,the electronic circuit of the present invention is relatively simple indesign such that preferably one electrode pair is necessary to conductdirect conductivity measurement. This can reduce costs and effort ascompared to known vascular access monitoring techniques that only employnon-invasive detection techniques, such as, capacitive couplers andinduction coils as previously discussed.

[0066] Applicants have discovered that the total impedance measured(“Z”) can be modeled as two lumped impedances in parallel with oneimpedance (“Z_(D)”) being produced by the pump segment, the dialyzer,the drip chambers and/or other suitable components of the dialysissystem and/or the like. The other impedance component (“Z_(P)”) isformed by the patient's vascular access and associated tubing whichcarries blood to and from the vascular access and/or the like. In thisregard, the total impedance measured can be characterized as a functionof both Z_(D) and Z_(P) as follows:

Z=(1/Z _(D)+1/Z _(P))⁻¹

[0067] Despite this parallel impedance, Applicants have discovered thatthe electrical contacts in connection with the controller can be used tomeasure a change in impedance along the conductor loop as blood flowsthrough the blood circuit in response to access disconnection, such asneedle dislodgment. If needle dislodgment occurs, the conductor loopalong at least a portion of the fluid circuit changes from a closedcircuit to an open circuit and thus Z=Z_(D) where Z_(P) approachesinfinity. In this regard, the direct conductive measurement capabilitiesof the present invention can be effectively used to detect accessdisconnection.

[0068] Applicants note that the Z_(D) component can produce a level ofelectrical interference associated with the time-varying high impedanceof the components of a medical system coupled to the fluid circuit, suchas a dialysis system and its components including, for example, a bloodpump, a drip chamber and/or the like. Applicants have discovered thatthe interference due to the Z_(D) component can be effectivelyeliminated, or at least reduced, if necessary. In an embodiment, thesignal associated with the detection of Z or the like can be furtherprocessed as discussed below. Alternatively, in an embodiment, theelectrical circuit of the present invention can be designed to block orbypass one or more components of the dialysis system from the conductorloop or pathway defined along the blood circuit as described below. Inthis regard, the accuracy, sensitivity and responsiveness with respectto the detection of access disconnection can be enhanced.

[0069] In an embodiment, a third electrical contact point 53 can beutilized to minimize or effectively eliminate the interferences withrespect to the high impedance components coupled to the blood circuit,such as the blood pump and the like. The additional contact point can bemade in any suitable way. For example, the third contact point can be anelectrode or other suitable device through which electrical continuitycan be established between it and one of the electrodes of the couplingdevices. In an embodiment, the third electrical contact can be attachedto a fluid circuit in fluid and electrical communication with fluidflowing through same.

[0070] The third contact point 53 can be positioned at any suitableposition along the blood circuit. Preferably, the third contact point 53is positioned at any suitable location between the blood pump 46 and thecoupling device 50 as shown in FIG. 1B. An equalization potential canthen be applied between the third contact point 53 and the electrode ofthe coupling device 50. The potential is applied at a voltage that isequal to the potential applied between the electrodes of the firstcoupling device 48 and the second coupling device 50.

[0071] This effectively causes the electric current or the like, onceinjected into the blood circuit, to bypass one or more of the componentsof the dialysis system. In an embodiment, the third contact point 53 canbe positioned such that the electric current or the like wouldeffectively bypass all of the components of the dialysis system as shownin FIG. 1B.

Single Access Disconnection

[0072] The electrical contacts of the present invention can bepositioned in any suitable location relative to the needle, needles orsuitable access device inserted within the patient. As illustrated inFIG. 1C, an embodiment of the present invention as applied with respectto the detection of access detection, such as the dislodgment of asingle access device inserted within the patient is shown. This type ofapplication is applicable to a variety of different and suitable medicaltherapies administered via a single access device, such as a singleneedle, including intravenous infusion and dialysis therapy includinghemodialysis, hemofiltration, hemodiafiltration and continuous renalreplacement.

[0073] As applied, an electrically conductive fluid, such as blood, ablood product, a medical fluid or the like flows between the patient anda fluid system via a single access device. Dislodgment detection of asingle access device can include, for example, the detection of needledislodgment during the delivery of any suitable and electricallyconductive fluid or fluids including, for example, blood or medical drugor solution (i.e., a medication contained in an electrically conductivefluid, such as saline), processed blood, blood products, intravenoussolutions, the like or combinations thereof. The fluid delivery can bemade between a suitable container, such as blood bags or like fluiddelivery devices, and a patient. In this regard, immediate andresponsive detection of access disconnection via the present inventioncan be effectively utilized to monitor and control the transfer of bloodor a medical fluid, such as a medication or drug, during medical therapyadministered via a single needle.

[0074] As shown in FIG. 1C, an embodiment of the apparatus or device 54of the present invention includes an access device 56; such as a needle,inserted into a blood vessel 58 within a needle insertion site 60 of thepatient 62. The needle 56 is connected to the fluid system 63, such as afluid infusion system, via a tube member 64. The infusion systemincludes, for example, an infusion pump 66 for transferring the blood orthe like from a container 68 (e.g., blood bag) to the patient. A firstelectrical contact 70 is spaced apart from the needle 56 along the tubemember 64 and a second electrical contact 72 is attached to the patientnear the insertion site 60. The first electrical contact 70 is in fluidcontact with the fluid as it flows from the delivery container 68 to thepatient.

[0075] In this configuration, the first and second electrical contacts,preferably electrodes, can be used to monitor changes in an electricalvalue, preferably impedance, within a conductor loop formed by at leasta portion of the fluid circuit as an electric signal passes therein. Inan embodiment, at least one of the electrical contacts can include aconductive polymer material as described below in greater detail. Theelectrical contact points can be coupled to an electronic device 74which is capable of processing a detectable signal transmitted throughthe electrodes in response to a change in impedance or the like due todislodgment of the single access device as described in detail below.Preferably, the electrical signal is generated by a constant currentsupplied to the electrodes such that a direct conductivity measurementcan be conducted to detect a change in impedance or the like in responseto changes in vascular access conditions, such as dislodgment of theaccess needle.

[0076] It is believed that the measured impedance, in the single needleapplication, is a function of both the impedance of the fluid (i.e.,blood) and the impedance as measured across the insertion site. In thisregard, the electronic device 74 can be adjusted to detect the impedanceat the level equivalent to the combined impedance of all items of theelectrical path (i.e., the conductive fluid in the tube, needle, bloodstream of venous vessel, body tissue, impedance across the skin withrespect to the sensing electrode 72 and the like).

Electrical Contacts

[0077] As previously discussed, the electrical contacts of the presentinvention are in fluid contact with the fluid as it flows through thefluid circuit. In this regard, the electrical contacts can be utilizedto monitor changes in conditions associated with patient therapy. Forexample, the electrical contacts allow for a direct conductivitymeasurement which is capable of immediately detecting, with highsensitivity and specificity, a change (e.g., an increase) in impedanceor the like due to access disconnection, such as dislodgment of a venousneedle (arterial needle or both) from the blood circuit during dialysistherapy. Other types of monitoring applications include monitoringconductivity changes in response to solution compounding as describedbelow in greater detail. It should be appreciated that the presentinvention can be utilized to monitor one or a combination of conditionchanges.

[0078] The electrical contacts can be composed of any suitableconductive and biocompatible material, such as, any suitable electrodematerial including stainless steel, other suitable conductive materialsor combinations thereof. It is essential that the electrode material isbiocompatible. In an embodiment, the electrical contact includes aconductive polymer material as described below in greater detail.

[0079] It should be appreciated that the electrical contacts can beconstructed in a variety of different shapes and sizes, illustrativeexamples of which are described below. For example, the electricalcontacts can be configured or designed as a plaster electrode whichincludes an agent capable of expanding when in contact with moisture.The agent can include a variety of suitable materials including gelsthat are known to expand more than ten times in volume upon contact withmoisture.

[0080] In an embodiment, the plaster electrode can be utilized to detectfluid (i.e., blood leakage) at an insertion site of an access deviceinsertable within a patient during the administration of medical therapyvia a single access device as previously discussed. Upon contact withthe fluid, the plaster electrode would necessarily expand to such anextent that the electrode contact is broken, thus causing a detectableincrease in impedance of the fluid as it flows from the fluid system tothe patient via the needle.

[0081] In an embodiment, one or more electrodes (not shown), such as oneor more plaster electrodes as previously discussed, can be used incombination with the electrical contact pair as shown, for example, inFIGS. 1A and 1B. For example, a plaster electrode can be attached to thepatient near the insertion site of either or both of the arterial andvenous needles. In this regard, the plaster electrode(s) can be utilizedto detect leakage of fluid, such as blood, from the insertion site ofthe access device(s).

[0082] In an embodiment, an electrode pair is coupled to the bloodcircuit in an invasive manner (illustrated in FIGS. 2A-2C as discussedbelow) such that the electrodes contact the blood as previouslydiscussed. An excitation source that includes a constant current sourceor the like can be applied to the electrodes to inject an electricsignal into the blood circuit thereby defining a conductor loop alongwhich direct conductivity measurements can be performed.

[0083] To ensure patient safety, the excitation source is typicallyisolated from the instrument power. Preferably, the excitation sourceproduces a constant electrical current that passes through the blood viathe electrodes. Any suitable amount of current can be generated fordetection purposes. In an embodiment, the electrical current as itpasses through the blood is maintained at a level of about 10microamperes or less, preferably about 5 microamperes or less. It shouldbe appreciated that the present invention can be operated at low levelsof current (e.g., 10 microamperes or less) such that the level ofcurrent has negligible, if any, effect on the health and safety of thepatient.

[0084] It should be appreciated that the impedance or other suitableparameter can be measured and calculated in a variety of different andsuitable ways. For example, the amplitude, phase and/or frequency of theconstant current excitation source can be measured and varied during thedetection of a change in impedance. Impedance levels can then bedetected by measuring the voltage across the electrodes In this regard,the amplitude, frequency and/or phase of the voltage can then bemeasured and utilized in combination with the measured amplitude,frequency and/or phase of the excitation source to calculate bloodimpedance levels based on derivations or equations which are typicallyused to calculate impedance.

[0085] The electrical contacts can be connected to the blood circuit ina variety of different and suitable ways. For example, the electricalcontacts can be an integral component of the extracorporeal system, adisposable component that can be connected and released from the tubingmembers of the blood circuit, a reusable component that can beautoclaved between uses, or the like.

Electrical Contact Coupling Device

[0086] In an embodiment, the apparatus of the present invention includesan electrical contact coupling device that can be utilized to secure theelectrical contacts, preferably electrodes, to the blood circuit suchthat the electrodes effectively contact the blood and, thus, can be usedto effectively monitor changes in access conditions as previouslydiscussed. In an embodiment, at least one of the electrical contactsincludes a conductive polymer material as described below. The couplingdevice of the present invention can also be designed to facilitate theprotection of the user against contact with potential electricalsources. In an embodiment, the device can include a conductive elementconnected to a tube, through which a medical fluid can flow wherein theconductive element has a first portion exposed to the medical fluid,such as blood, and a second portion external to the tube.

[0087] The coupling device of the present invention can include avariety of different and suitable configurations, components, materialmake-up or the like. In an embodiment, the present invention can includea device for connecting an electrical contact to a fluid conduitproviding fluid and electrical communication between the electricalcontact and fluid flowing through the fluid conduit. The device caninclude a first member including an annular portion capable ofaccommodating the electrical contact and a first stem portion connectedto the annular member wherein the stem portion has an opening extendingtherethrough to the annular portion; a second member including a baseportion with a groove region and a second stem portion with an openingextending therethrough to the groove region allowing the first member tobe inserted and secured to the second member; and a contact memberadapted to fit the first and second stem portions allowing the contactmember to abut against at least a portion of the electrical contactmember allowing an electrical connection to be made between theelectrical contact and the contact member. Illustrative examples of theelectrical contact coupling device of the present invention aredescribed below.

[0088] As illustrated in FIGS. 2A and 2B, the electrical contactcoupling device 80 includes a probe member 82 that has a cylindricalshape with an opening 84 extending therethrough. In this regard, anelectrical contact, preferably an electrode 86 having a cylindricalshape can be inserted into the opening 84 such that the electrode 86 issecure within the probe member 82. In an embodiment, the probe member 82has a channel 85 extending along at least a portion of the opening 84within which the electrode 86 can be inserted into the probe member 82.A tube member, for example, from a blood tubing set, connector tubemember of a dialysis machine or the like, can be inserted into both endsof the opening 84 of the probe member 82 in contact with an outerportion of the channel 85 allowing blood or other suitable fluid to makefluid contact with the electrode 86 in any suitable manner. Theelectrode 86 has an opening 88 that extends therethrough within whichblood (not shown) or other suitable fluid from the fluid circuit canflow. In an embodiment, the diameter of the opening 88 of the electrode86 is sized to allow blood flow through the electrode 86 such that bloodflow levels under typical operating conditions, such as during dialysistherapy, can be suitably maintained. In this regard, the coupling deviceof the present invention can be readily and effectively attached to afluid circuit, including a blood circuit or the like, for use duringmedical therapy including, for example, dialysis therapy. It should beappreciated that the coupling device 80 of the present invention can beattached to the fluid circuit in any suitable way such that electricaland fluid connection can be made with the fluid flowing through thefluid circuit.

[0089] The probe member 82 also includes a stem portion 90 that extendsfrom a surface 92 of its cylindrical-shaped body. The stem portion 90has an opening 93 that extends therethrough. In an embodiment, the stemportion 90 is positioned such that at least a portion of the electrode86 is in contact with the opening 93 of the stem portion 90.

[0090] In order to secure the electrode 86 to the blood circuit, thecoupling device 80 includes a socket member 94 that includes a bodyportion 96 with an opening 98 for accepting the probe member 82 and foraccepting a blood tube member (not shown) of the blood circuit such thatblood directly contacts the electrode as it circulates through the bloodcircuit during dialysis therapy. In an embodiment, the socket member 94includes a stem portion 100 extending from the body member 96 whereinthe stem portion 100 includes an opening 102 extending therethrough. Asthe probe member 82 is inserted through the opening 98 of the bodymember 96, the stem portion 90 of the probe member 82 can be insertedinto the opening 102 of the stem portion 100 of the body 96 of thesocket member 94.

[0091] In an embodiment, the socket member 94 includes a groove region104 extending along at least a portion of the body 96 of the socketmember 94. In this regard, the probe member 82 can be inserted throughthe opening 98 and then moved or positioned into the groove region 104to secure the probe member 82 within the body 96 of the socket member94.

[0092] In an embodiment, the coupling device 80 includes an electricalcontact member 106 that is inserted within the opening 102 of the stemportion 100 of the body 96 of the socket member 94 such that theelectrical contact member 106 extends through the opening 93 of the stemportion 90 of the probe member 82 to contact at least a portion of asurface 108 of the electrode 86.

[0093] The electrical contact member 106 is utilized to connect theelectronics (not shown) of, for example, the excitation source, a signalprocessing device, other like electronic devices suitable for use inmonitoring and/or controlling changes in access conditions, such asneedle dislodgment. The electrical contact member 106 can be made of anysuitable material, such as any suitable conductive material including,stainless steel, other like conductive materials or combinationsthereof. In order to secure the electrical contact member 106 in place,a contact retainer member 110 is inserted within the opening 102 of thestem portion 100 at an end region 112 thereof.

[0094] In an embodiment, the coupling device is mounted to a dialysismachine, device or system in any suitable manner. For example, thecoupling device can be mounted as an integral component of the dialysismachine. As well, the coupling device can be mounted as a separateand/or stand alone component which can interface with any of thecomponents of the apparatus and system of the present invention. In anembodiment, the coupling device 80 can be insertably mounted via thestem portion 100 of the socket member 94 to a dialysis machine or othersuitable components.

[0095] It should be appreciated that the electrical contact couplingdevice can include a variety of different and suitable shapes, sizes andmaterial components. For example, another embodiment of the couplingdevice is illustrated in FIG. 2C. The coupling device 114 in FIG. 2C issimilar in construction to the coupling device as shown in FIGS. 2A and2B. In this regard, the coupling device 114 of FIG. 2C can include, forexample, a cylindrical-shaped electrode or other suitable electricalcontact, a probe member for accepting the electrode and securing it inplace within a socket member of the sensing device. The probe memberincludes a stem portion that is insertable within a stem portion of thesocket member. An electrical contact member is insertable within thestem portion such that it can contact the electrode. The coupling deviceof FIG. 2C can also include a contact retainer member to hold theelectrical contact member in place similar to the coupling device asshown in FIGS. 2A and 2B.

[0096] As shown in FIG. 2C, the probe member 116 of the electricalcontact coupling device 114 includes a handle 118 which can facilitatesecuring the probe member 116 within the socket member 120. The handle118, as shown, has a solid shape which can facilitate the use andmanufacture of the coupling device 114. In addition, the stem portion(not shown) of the probe member 116 is larger in diameter than the stemportion of the probe member as illustrated in FIG. 2A. By increasing thestem size, the probe member can be more easily and readily insertedwithin the socket member. Further, the probe member is greater in lengthas compared to the probe-member as shown in FIGS. 2A and 2B such thatthe end regions 122 of the probe member 116 extend beyond a grooveregion 124 of the socket member 120. This can facilitate securing theprobe member within the groove region 124 of the socket member 120.

[0097] In an embodiment, an opening 126 of the socket member 120 caninclude an additional opening portion 128 to accommodate the insertionof the stem portion of the probe member 116, having an increased size,therethrough. This can ensure proper alignment of the probe member withrespect to the socket member before insertion of the probe member intothe socket member thus facilitating the insertion process.

[0098] It should be appreciated that the probe member, socket member andcontact retainer member can be composed of a variety of different andsuitable materials including, for example, plastics, molded plastics,like materials or combinations thereof. The various components of thecoupling device, such as the probe member, socket member and contactretainer member, can be fitted in any suitable way. For example, thecomponents can be fitted in smooth engagement (as shown in FIGS. 2A and2B), in threaded engagement (as shown in FIGS. 2D and 2E) and/or anysuitable fitting engagement or arrangement to one another.

[0099] As shown in FIGS. 2D and 2E, the coupling device 130 of thepresent invention can be made of threaded parts which are removablyconnected to one another to form the coupling device. The threaded partscan facilitate securing the electrode to the blood circuit as well asgeneral use of same as described below.

[0100] In an embodiment, the stem portion 132 of the body 134 of thecoupling device 130 has a threaded region 136 which can be insertablyattached to a dialysis machine or other suitable mounting device inthreaded engagement. This can facilitate the ease in which the couplingdevice is attached and detached from the mounting device.

[0101] As shown in FIG. 2E, the stem portion 132 is threaded on bothsides allowing it to be in threaded engagement with an annular member138. The annular member 138 provides direction and support allowing theelectrical contact member 140 to abut against the electrode 142 housedin the probe member 144 as previously discussed.

[0102] In an embodiment, a plate member 146 made of any suitableconductive material can be depressed against a spring 148 as the probemember 144 is secured to the body 134. At the same time, another spring150 can be displaced against the electrical contact member 140 incontact with the retainer 152 which is inserted within an annular regionof the annular member 138 to secure the electrical contact member 140 tothe body 134.

[0103] The spring mechanism in an embodiment of the present inventionallows the parts of the coupling device 130 to remain in secureengagement during use. It can also facilitate use during detachment ofthe parts for cleaning, maintenance or other suitable purpose.

[0104] As previously discussed, the present invention can be effectivelyutilized to detect dislodgment of an access device, such as a needle,inserted within a patient through which fluid can pass between thepatient and a fluid delivery and/or treatment system. The presentinvention can be applied in a number of different applications, such asmedical therapies or treatments, particularly dialysis therapies. Indialysis therapies, access devices, such as needles, are inserted into apatient's arteries and veins to connect blood flow to and from thedialysis machine.

[0105] Under these circumstances, if the needle becomes dislodged orseparated from the blood circuit, particularly the venous needle, theamount of blood loss from the patient can be significant and immediate.In this regard, the present invention can be utilized to controllablyand effectively minimize blood loss from a patient due to dislodgment ofthe access device, such as during dialysis therapy includinghemodialysis, hemofiltration, hemodiafiltration and continuous renalreplacement.

Signal Detection and Processing

[0106] As previously discussed, the electrical contacts in connectionwith the controller can be used to detect a change in impedance or thelike in response to needle drop-out or other like changes in accessconditions. The electrical contacts can include a variety of suitableconductive materials, such as conductive polymer materials as describedbelow. In an embodiment, the present invention can be adapted to correctfor any variations in the baseline impedance over time. This canincrease the level of sensitivity with respect to the detectioncapabilities of the present invention. In this regard, if changes in thebaseline impedance are too great and not adequately corrected for,changes in impedance due to needle dislodgment may not be as readily, ifat all, detectable above baseline values.

[0107] From a practical standpoint, there are a number of differentprocess conditions that may influence a change in the baseline impedanceover time. For example, a gradual drift or change in the baseline canoccur due to a change in the characteristics, such as the hematocrit,plasma protein, blood/water conductivity and/or the like, of the bloodor other suitable fluid during treatment. This can arise due to changesin the level of electrolytes or other components during dialysistherapy.

[0108] As illustrated in FIG. 3, the present invention can process ameasurable voltage signal to correct for changes in baseline impedanceover time. This can enhance the detection capabilities of the presentinvention as previously discussed. In an embodiment, a current source160 or the like generates an electric current to pass through the bloodas it circulates into, through and out of the patient along theextracorporeal blood circuit 162 which connects the patient via venousand arterial needles to the dialysis system including a variety ofprocess components. The electric current is injected into the bloodcircuit via a first electrical contact 163 a thereby defining aconductor loop or pathway along the blood circuits. Preferably, thecurrent is maintained at a constant level until dislodgment occurs. Thesecond electrode 163 b is used to sense voltage or the like along theconductor loop and then pass a signal indicative of same and/or changesthereof to an electronic device for detection and processing aspreviously discussed. The voltage signal can be measured and processedin any suitable manner.

[0109] In an embodiment, the signal is passed through a series ofcomponents including a filter or filters 164 which can act to filternoise from the signal, particularly noise derived from the rotation fromthe pump in order to minimize a false negative and/or positive detectionof needle dislodgment, a rectifier 166, a peak detector 168 and ananalog to digital converter (“ADC”) 170 to digitize the signal. In thisregard, the digital signal can then be stored in a computer device (notshown) for further processing. The voltage signal is continuallymeasured and processed over time. With each measurement, the digitizedsignals are compared to evaluate changes due to baseline changesassociated with variations in process conditions over time, such as achange in the characteristics of blood as previously discussed. If abaseline change is determined, the digitized signal can be furtherprocessed to correct for the change in baseline.

[0110] The voltage data is continually sent to a control unit 172coupled to the ADC. The control unit continually performs a calculationto determine whether a change in impedance or the like in response toneedle dislodgment has occurred. In an embodiment, dislodgment of anaccess device is detected when [V(t)−V(t−T)]>C1, where t is time, whereT is the period of blood pump revolution, where C1 is a constant andwhere V(t)=I_(o)*Z, where I_(o) is current and where Z is the impedanceof the bloodline which is a function of the impedance associated withpatient's vascular access and the impedance associated with variouscomponents of the dialysis system, such as the dialyzer, as previouslydiscussed.

[0111] If disconnection of the patient from the blood circuit isdetected, the control unit 172 can be utilized to process the signal inorder to minimize blood loss from the patient. In an embodiment, thecontroller is in communication with a dialysis system as applied toadminister dialysis therapy including, for example, hemodialysis,hemofiltration, hemodiafiltration and continuous renal replacement. Thiscommunication can be either hard-wired (i.e., electrical communicationcable), a wireless communication (i.e., wireless RF interface), apneumatic interface or the like. In this regard, the controller canprocess the signal to communicate with the dialysis system or device toshut off or stop the blood pump 174 associated with the hemodialysismachine and thus effectively minimize the amount of blood loss from thepatient due to needle dislodgment during hemodialysis.

[0112] The controller can communicate with the dialysis system in avariety of other ways. For example, the controller and hemodialysismachine can communicate to activate a venous line clamp 176 forpreventing further blood flow via the venous needle thus minimizingblood loss to the patient. In an embodiment, the venous line clamp isactivated by the controller and attached to or positioned relative tothe venous needle such that it can clamp off the venous line in closeproximity to the needle. Once clamped, the dialysis system is capable ofsensing an increase in pressure and can be programmed to shut-off theblood pump upon sensing pressure within the blood flow line which isabove a predetermined level. Alternatively, the venous line clamp can becontrollably attached to the dialysis system.

[0113] In an embodiment, an alarm can be activated upon detection ofblood loss due to, for example, needle dislodgment during dialysistherapy. Once activated, the alarm (i.e., audio and/or visual or thelike) is capable of alerting the patient, a medical care provider (i.e.,doctor, registered nurse or the like) and/or a non-medical care provider(i.e., family member, friend or the like) of the blood loss due to, forexample, needle dislodgment. The alarm function is particularlydesirable during dialysis therapy in a non-medical facility, such as ina home setting or self care setting where dialysis therapy is typicallyadministered by the patient and/or a non-medical care provider in anon-medical setting or environment excluding a hospital or other likemedical facility.

[0114] In this regard, the alarm activation allows, for example, thepatient to responsively act to ensure that the dialysis therapy isterminated by, for example, to check that the blood pump has beenautomatically shut off to minimize blood loss to the patient. Thus, thepatient has the ability to act without the assistance of a third party(i.e., to act on his or her own) to ensure that responsive measures aretaken to minimize blood loss. The alarm can thus function to ensure thepatient's safety during the administration of dialysis therapy,particularly as applied to home hemo treatments where at least a portionof the dialysis therapy can be administered while the patient issleeping.

Dialysis Machine

[0115] As previously discussed, the present invention can be adapted foruse with any suitable fluid delivery system, treatment system or thelike. In an embodiment, the present invention is adapted for use with adialysis machine to detect access disconnection as blood flows betweenthe patient and the dialysis machine along a blood circuit duringtreatment, including, for example hemodialysis, hemofiltration andhemodiafiltration.

[0116] The present invention can include any suitable dialysis machinefor such purposes. An example, of a hemodialysis machine of the presentinvention is disclosed in U.S. Pat. No. 6,143,181 herein incorporated byreference. In an embodiment, the dialysis machine 190 includes a mobilechassis 192 and it has at the front side 194 thereof a common mechanism196 for connecting tubing or the like by which a patient can beconnected to the dialysis machine as shown in FIG. 4B. A flat touchscreen 197 which can show several operational parameters and is providedwith symbols and fields for adjustment of the dialysis machine byrelevant symbols and fields, respectively, on the screen being touchedcan be adjusted vertically and can be universally pivoted on thedialysis machine and can be fixed in the desired adjusted position.

[0117] In an embodiment, the dialysis machine includes a chassis havingone or more connectors for connecting a patient to the dialysis machinevia a blood circuit allowing blood to flow between the patient and thedialysis machine during dialysis therapy wherein one or more electricalcontacts are connected to the blood circuit in fluid communication withthe blood allowing detection of a change in an electrical value inresponse to access disconnection as the blood flows through the bloodcircuit having an electrical signal passing therein.

[0118] In an embodiment, the dialysis machine of the present inventioncan be designed to accommodate one or more of the electrical contactcoupling devices, such as a pair of coupling device, used to detectaccess disconnection as shown in FIG. 4B. For example, one or morecoupling devices 198 can be attached to the front panel 194 of thedialysis machine 190. This can be done in any suitable way. In anembodiment, the a stem portion of the coupling device is insertablymounted via- a threaded fit, frictional fit or the like, as previouslydiscussed. This connects the patient to the dialysis machine 190 via ablood tubing set 202. The blood tubing set includes a first blood line204 and a second blood line 206. In an embodiment, the first blood line204 is connected to the patient via an arterial needle 208 or the likethrough which blood can flow from the patient 200 to the dialysismachine 190. The second blood line 206 is then connected to the patient200 via a venous needle 210 or the like through which fluid flows fromthe dialysis machine to the patient thereby defining a blood circuit.Alternatively, the first blood line and the second blood line can becoupled to the venous needle and the arterial needle, respectively. Theblood lines are made from any suitable medical grade material. In thisregard, access disconnection, such as dislodgment of an arterial needleand/or a venous needle can be detected as previously discussed.Alternatively, the coupling device can be attached to the blood tubingset which is then attached to the dialysis machine in any suitable way.

Dialysis Treatment Centers

[0119] As previously discussed, the present invention can be used duringdialysis therapy conducted at home and in dialysis treatment centers.The dialysis treatment centers can provide dialysis therapy to a numberof patients. In this regard, the treatment centers include a number ofdialysis machines to accommodate patient demands. The therapy sessionsat dialysis treatment centers can be performed 24 hours a day, sevendays a week depending on the locale and the patient demand for use.

[0120] In an embodiment, the dialysis treatment centers are providedwith the capability to detect access disconnection during dialysistherapy pursuant to an embodiment of the present invention. For example,one or more of the dialysis machines can be adapted for use with anelectrical contact coupling device along with the necessary othercomponents to detect access disconnection as previously discussed.

[0121] In an embodiment, the electrical contact coupling device can bedirectly attached to one or more of the dialysis machines of thedialysis treatment center. It should be appreciated that theapparatuses, devices, methods and/or systems pursuant to an embodimentof the present invention can be applied for use during dialysis therapyadministered to one or more patients in the dialysis treatment center inany suitable way. In an embodiment, the treatment center can have one ormore patient stations at which dialysis therapy can be performed on oneor more patients each coupled to a respective dialysis machine. Anysuitable in-center therapy can be performed including, for example,hemodialysis, hemofiltration and hemodiafiltration and combinationsthereof. As used herein, the term “patient station” or other like termsmean any suitably defined area of the dialysis treatment centerdedicated for use during dialysis therapy. The patient station caninclude any number and type of suitable equipment necessary toadminister dialysis therapy.

[0122] In an embodiment, the dialysis treatment center includes a numberof patient stations each at which dialysis therapy can be administeredto one or more patients; and one or more dialysis machines located at arespective patient station. One or more of the dialysis machines caninclude a chassis having one or more connectors for connecting a patientto the dialysis machine via a blood circuit allowing blood to flowbetween the patient and the dialysis machine during dialysis therapywherein a pair of electrical contacts are connected to the blood circuitin fluid communication with the blood allowing detection of a change inan electrical value in response to access disconnection as the bloodflows through the blood circuit having an electrical signal passingtherein.

[0123] As previously discussed, the access disconnection detectioncapabilities of the present invention can be utilized to monitor andcontrol a safe and effective dialysis therapy. Upon dislodgment of anaccess device, such as a needle, from the patient, the direct conductivemeasurement capabilities of the present invention can be used to providea signal indicative of dislodgment that can be further processed forcontrol and/or monitoring purposes. In an embodiment, the signal can befurther processed to automatically terminate dialysis therapy tominimize blood loss due to dislodgment as previously discussed. Further,the signal can be processed to activate an alarm which can alert thepatient and/or medical personnel to the dislodgment condition to ensurethat responsive measures are taken. It should be appreciated that thepresent invention can be modified in a variety of suitable ways tofacilitate the safe and effective administration of medical therapy,including dialysis therapy.

[0124] Applicants have found that the direct conductive measurementcapabilities of the apparatus of the present invention can immediatelydetect blood loss or the like due to access disconnection, such asneedle dislodgment, with high sensitivity and selectivity such thatresponsive measures can be taken to minimize blood loss due to same. Theability to act responsively and quickly to minimize blood loss upondetection thereof is particularly important with respect to needledislodgment during hemodialysis. If not detected and responded toimmediately, the amount of blood loss can be significant. In anembodiment, the present invention is capable of taking active orresponsive measures, to minimize blood loss (i.e., shut-off blood pump,activate venous line clamp, activate alarm and/or the like) within aboutthree seconds or less, preferably within about two to about three secondupon immediate detection of needle dislodgment.

[0125] In addition, the controller can be utilized to monitor and/orcontrol one or more treatment parameters during hemodialysis. Theseparameters can include, for example, the detection of blood due to bloodloss upon needle dislodgment, the change in blood flow, the detection ofair bubbles in the arterial line, detection of movement of the sensorduring treatment, detection and/or monitoring of electrical continuityof the sensor or other like treatment parameters. In an embodiment, thecontroller includes a display (not shown) for monitoring one or more ofthe parameters. Thus, the present invention can be utilized to promotethe safe and effective administration on patient therapy, such asdialysis therapy, as previously discussed.

[0126] As used herein “medical care provider” or other like termsincluding, for example, “medical care personnel”, means an individual orindividuals who are medically licensed, trained, experienced and/orotherwise qualified to practice and/or administer medical proceduresincluding, for example, dialysis therapy, to a patient. Examples of amedical care provider include a doctor, a physician, a registered nurseor other like medical care personnel.

[0127] As used herein “non-medical care provider” or other like termsincluding, for example, “non-medical care personnel” means an individualor individuals who are not generally recognized as typical medical careproviders, such as doctors, physicians, registered nurses or the like.Examples of non-medical care providers include patients, family members,friends or other like individuals.

[0128] As used herein “medical facility” or other like terms including,for example, “medical setting” means a facility or center where medicalprocedures or therapies, including dialysis therapies, are typicallyperformed under the care of medical care personnel. Examples of medicalfacilities include hospitals, medical treatment facilities, such asdialysis treatment facilities, dialysis treatment centers, hemodialysiscenters or the like.

[0129] As used herein “non-medical facility” or other like termsincluding, for example, “non-medical setting” means a facility, center,setting and/or environment that is not recognized as a typical medicalfacility, such as a hospital or the like. Examples of non-medicalsettings include a home, a residence or the like.

[0130] It should be appreciated that the electrode output signal can becombined with other less sensitive blood loss detection methods, such asvenous pressure measurements, systemic blood pressure, the like orcombinations thereof, to improve specificity to needle dislodgment.

Conductive Polymer

[0131] As previously discussed, the present invention providesconductive polymer materials and devices, apparatuses, systems andmethods that employ same. The conductive polymer material can beutilized in a number of different applications, such as to monitorpatient therapy. For example, the conductive polymer materials can beutilized to monitor patient access conditions as discussed above and asfurther detailed below. Other types of monitoring applications include,for example, monitoring solution mixing or compounding as described ingreater detail below. The present invention contemplates monitoring oneor a combination of condition changes associated with patient therapy,such as monitoring patient access conditions and solution mixingconditions, alone or in combination.

[0132] In an embodiment, the conductive polymer material includes apolymer matrix and a conductive component that is incorporated in thepolymer matrix. Alternatively, the conductive polymer material, in anembodiment, includes a conductive polymer component without a separateconductive component, such as stainless steel. It should be appreciatedthat the conductive polymer material can be made from any suitable typesand amounts of materials and in any suitable way.

[0133] As discussed above, the conductive polymer can include a polymermatrix and a conductive component incorporated in the matrix. Thepolymer matrix can include a variety of different polymer-basedmaterials that are suitable for use in a variety of applications,particularly including medical applications, such as dialysis therapy.In an embodiment, the polymer matrix includes polyvinyl chloride,acrylonitrile butadiene styrene, polycarbonate, acrylic, a cyclo olefincopolymer, a cyclo olefin copolymer blend, a metallocene-basedpolyethylene, like polymeric materials and suitable combinationsthereof.

[0134] The conductive component can include any suitable material orcombination of materials that have conductive properties applicable fora number of different applications including, for example, detectingpatient access disconnection during medical therapy as previouslydiscussed, monitoring the mixing or compounding of solution componentsto form a mixed solution, and/or other like applications. Preferably,the conductive component includes stainless steel, fillers, carbonblack, fibers thereof and/or the like.

[0135] The conductive component can be sized and shaped in any suitableway such that it can be readily incorporated in the polymer matrix. Forexample, the conductive component can include conductive fibers madefrom any suitable material, such as stainless steel, a carbonaceousmaterial and/or the like. The fibers, in an embodiment, have an aspectratio that ranges from about 2:1 to about 30:1.

[0136] The conductive polymer material can include any suitable amountof the conductive polymer matrix and the conductive component. This canvary depending on the application of the conductive polymer material. Inan embodiment, the conductive component includes greater than about 10%by weight of the conductive polymer material. Preferably, the conductivecomponent ranges from about 10% to about 50% by weight of the conductivepolymer material. It should be appreciated that more than about 50% byweight of the conductive component can be utilized but may provideminimal, if any, increase in performance of the conductive polymermaterial depending on the application. Preferably, the conductivecomponent is uniformly dispersed throughout the polymer matrix.

[0137] As previously discussed, the conductive polymer material, in anembodiment, is composed of a conductive polymer component. This type ofcomponent has sufficient electrical conductivity properties such that anadditional conductive component, such as stainless steel, is notrequired. Examples of conductive polymer material components includepolyaniline, polypyrrole, polythiophenes, polyethylenedioxythiophene,poly(p-phenylene vinylene), the like and mixtures thereof.

[0138] As previously discussed, the conductive polymer material can bemade in any suitable way. In general, the conductive component is mixedwith the polymer component under suitable processing conditionsincluding temperature and pressure, for example, to form a polymermatrix with the conductive component incorporated therein. The mixingshould take place over a suitable period of time and with a sufficientamount of force such that the conductive component is uniformlydistributed throughout the polymer matrix.

[0139] The polymer matrix incorporated with a conductive component isthen shaped and formed into a final product in any suitable way. Forexample, the polymer matrix incorporated with the conductive componentcan be formed into a single piece part via an injection molding process,extrusion process or the like under suitable processing conditions.Thus, the conductive polymer material can be readily made withmanufacturing techniques, such as injection molding and extrusion. Thiscan effectively provide a cost savings to the manufacturing process thatcan be inevitably passed along to the consumer.

[0140] The conductive polymer material can be formed into any suitableshape and size depending on the application. In an embodiment, theconductive polymer material is formed into an electrode or other likeelectrical contact that can be utilized for a number of differentapplications, including, for example, monitoring patient accessconditions and/or monitoring solution mixing or compounding as discussedabove and described below in greater detail. The conductive polymerelectrode can have a variety of different and suitable configurationsdepending on the application. For example, the conductive polymerelectrode can be made into a coupler that can be used to join tubing toform a tubing joint as described below.

[0141] As shown in FIGS. 5A and 5B, the conductive polymer coupler has agenerally cylindrical shape. With this configuration, the conductivepolymer can be readily attached to a tube through which fluid flows,thus forming a tubing joint.

[0142] As shown in FIG. 5A, the coupler 220 has a member 222 thatextends from an inner surface 224 of the coupler electrode 220. Themember 222 acts as a stop for the tube 226 that is attached to theelectrode such that a desired length of the tubing joint 228 can bepreset. The coupler 220 as shown in FIG. 5A, in an embodiment, is madevia an injection molding process.

[0143] As shown in FIG. 5A, a first tube member 230 is attached to afirst end 232 of the coupler 220 and positioned or stopped by a firstend 234 of the member 222. A second tube member 236 is attached to asecond end 238 of the coupler 220 and stopped or positioned by a secondend 240 of the member 222. This forms a tubing joint 228, such as atubing joint that is integrated within a blood circuit and utilizedduring dialysis therapy as described in the present application.

[0144] As shown in FIG. 5B, the coupler 242 is formed without a memberthat allows the length of the tubing joint to be preset as discussedabove. In this regard, the tubing joint length can be adjustedaccordingly depending on the application. Further, the coupler 242 asshown in FIG. 5B can be made via an extrusion process instead of aninjection molding process. This can provide a further cost savings withrespect to manufacturing of the coupler as compared to an injectionmolding process as discussed above. As shown in FIG. 5B, a first tubemember 244 is attached to a first end 246 of the coupler 242 and asecond tube member 248 is attached to the second end 250 of the coupler242, thus forming the tubing joint 252.

[0145] The tube member can be attached to the conductive polymer couplerin any suitable way. For example, the conductive polymer material can besolvent bonded, heat sealed, laser welded, radio frequency sealed, orthe like to the tubing.

[0146] The tubing can be made of any suitable material depending on theapplication. For example, the tubing can be made from polyvinyl chloride(“PVC”). Preferably, the PVC tubing is attached to a conductive polymermaterial that is made with a polymer matrix composed of acrylonitrilebutadiene styrene (“ABS”) where the ABS-based conductive material issolvent bonded to the PVC tubing.

[0147] However, the tubing can be made of a variety of differentmaterials depending on the application. In an embodiment, the tubingincludes a non-PVC material, such as metallocene-based polyethylenepolymers, cyclo olefin copolymers, cyclo olefin copolymer blends and thelike. The non-PVC materials can include any suitable type and amount ofconstituents. Metallocene-based polyethylene polymers and the likeillustrative of the present invention can be found, for example, in U.S.Pat. No. 6,372,848, the disclosure of which is herein incorporated byreference. These types of non-PVC polymers can include a polymer blendthat has a first ethylene and α-olefin copolymer obtained using a singlesite catalyst present in an amount by weight of from about 0% to about99% by weight of the blend and having a melt flow index from fractional,such as about 0.1 g/10 min to about 5 g/10 min, a second ethylene andα-olefin copolymer obtained using a single site catalyst and beingpresent in an amount by weight of the blend from about 0% to about 99%and having a melt flow index from higher than about 5 g/10 min to about20 g/10 min; and a third ethylene and α-olefin copolymer obtained usinga single-site catalyst and being present in an amount by weight of theblend from about 0% to about 99% and having a melt flow index greaterthan about 20 g/10 min. In an embodiment, the α-olefin copolymer has amolecular weight distribution of less than about 3.

[0148] Cyclo olefin copolymers and blends thereof illustrative of thepresent invention can be found, for example, in U.S. Pat. No. 6,255,396,the disclosure of which is herein incorporated by reference. These typesof non-PVC polymers can include as a component homopolymers orcopolymers of cyclic olefins or bridged polycyclic hydrocarbons. Forexample, the polymer composition includes a first component obtained bycopolymerizing a norbomene monomer and an ethylene monomer wherein thefirst component is in an amount from about 1-99% weight of thecomposition; and a second component of an ethylene and α-olefincopolymer that has six carbons wherein the second component is in anamount from about 99% to about 1% by weight of the composition. In anembodiment, the polymer composition can include an additional component,such as a second homopolymer or copolymer of a cyclic olefin or abridged polycyclic hydrocarbon.

[0149] The non-PVC based tubing and the non-PVC based conductive couplercan be joined in any suitable way to form a tubing joint. In anembodiment, the non-PVC based tubing and coupler are joined via solventbonding, such as disclosed in U.S. Pat. Nos. 6,255,396 and 6,372,848. Asused herein the term solvent bonding or other like terms means that thetubing can be exposed to a solvent to melt, dissolve or swell the tubingand then be attached to another polymeric component to form a permanentbond. Suitable solvents typically include those having a solubilityparameter of less than about 20 (Mpa)^(1/2). Suitable solvents can alsohave a molecular weight less than about 200 g/mole. The solvent caninclude, for example, aliphatic hydrocarbons, aromatic hydrocarbons, andmixtures thereof. As used herein, the terms aliphatic hydrocarbon andaromatic hydrocarbon are compounds containing only carbon and hydrogenatoms.

[0150] Suitable aliphatic hydrocarbons can include substituted andunsubstituted hexane, heptane, cyclohexane, cycloheptane, decalin andthe like. Suitable aromatic hydrocarbons can include substituted andunsubstituted aromatic hydrocarbon solvents, such as xylene, tetralin,toluene, cumene and the like. Suitable hydrocarbon substituents caninclude aliphatic substituents that have from 1-12 carbons and includepropyl, ethyl, butyl, hexyl, tertiary butyl, isobutyl, the like andcombinations thereof.

[0151] As previously discussed, the conductive polymer of the presentinvention can be constructed and arranged into a variety of differentconfigurations, such as a conductive polymer coupler as shown in FIGS.5A and 5B and discussed above. Another example includes a dialyzerheader that is made from the conductive polymer according to anembodiment. Referring to FIG. 6, a dialyzer 253 is generallyillustrated. The dialyzer 253 includes a body member 254 that generallyincludes a casing 256. The casing 256 includes a core section as well astwo bell members 260 located at each end of the dialyzer. Located withinthe core is a fiber bundle 258. The dialyzer also includes a dialysateinlet 262 and a dialysate outlet 264.

[0152] Located at a first end 266 of the dialyzer 253 is a fluid inlet268 and at a second end 270 is a fluid outlet 272 defined by a fluidinlet header 274 and a fluid outlet header 276, respectively. Thedialyzer 253 is connected to a dialysis blood circuit in any suitablemanner. In an embodiment, the inlet 274 and outlet 276 headers are madefrom the conductive polymer material of the present invention asdiscussed above. The inlet 274 and outlet 276 headers can be connectedto a controller 278 such that the conductive polymer headers can beutilized to monitor patient access conditions as previously discussed.

[0153] A variety of different header and dialyzer designs can beutilized. For example, U.S. Pat. No. 6,623,638 and U.S. PatentPublication No. 2003/0075498 provide a number of different examplesillustrative of the present invention. The disclosures of U.S. Pat. No.6,623,638 and U.S. Patent Publication No. 2003/0075498 are hereinincorporated by reference.

[0154] The conductive polymer of the present invention can be utilizedin any suitable way and in a variety of different devices, apparatuses,systems and applications thereof. For example, the conductive polymercan be utilized to detect a change in impedance in response todislodgement of an access device, to detect a change in conductivity inresponse to a change in solution composition and/or other suitableapplications.

[0155] In an embodiment, the conductive polymer is part of a sensorassembly or apparatus that can be utilized, for example, for monitoringdialysis applications as discussed in the present application. Thesensor apparatus of the present invention can include a number ofdifferent configurations and designs. Two examples of such designsillustrative of the present invention are described below in FIGS. 7Aand 7B.

[0156] In FIG. 7A, the tubing joint 284 that includes the conductivepolymer electrode 286 attached to a tube member 288 as described above,for example, is positioned in place by a holding device 290 or holderfor purposes of detection capabilities associated with the sensorapparatus 291 in an embodiment. In general, the holder 290 as shown inFIG. 7A has a hub design. More specifically, the holder 290 includes abase member 292 onto which the tubing joint 284 can be placed. The basemember 292 includes a first portion 294 that is made from a plastic orother suitable material. The first portion 294 defines an outer surface296 of the base member 292. Along the outer surface 296, the firstportion 294 includes two openings that are spaced apart as shown in FIG.7A. The first opening 298 is located on a first edge 300 of the firstportion of the base and the second opening 302 is located on a secondedge 304 of the first portion of the base. The openings can beconfigured in any suitable way and be utilized for mounting purposes.

[0157] The second portion of the base member includes a conductiveportion 306 as shown in FIG. 7A. In an embodiment, the conductiveportion 306 includes a single piece part 308 that is made from anysuitable conductive material, such as stainless steel and/or the like.As shown in FIG. 7A, the conductive polymer of the tubing joint isplaced against a curved edge 310 of the second portion thatsubstantially forms to an outer surface 312 of the conductive polymerelectrode 286. The electrode is substantially cylindrical in shape.

[0158] The holder 290 further includes an arm member 314 that ispivotally attached to the base member 292 as shown in FIG. 7A. The armmember 314 includes a generally curved region such that the arm 314 canbe positioned over the tubing joint 284 allowing it to substantiallyconform to the generally cylindrical surface of the tube joint and thusfurther securing the tubing joint 284 in place.

[0159] Another configuration of a hub design illustrative of the sensorapparatus of the present invention is shown in FIG. 7B. In general, thisdesign provides a box-like holder 316 that encloses the tubing joint 318wherein the tubing joint includes the conductive polymer electrode 320in the form of a coupler that is attached to the tube member 322 asdiscussed above. The holder 316 includes a base member 324. The basemember 324 includes side portions 326, a bottom portion 328 and anopening 330 at a top portion 332. As shown in FIG. 7B, the sensorapparatus 334 includes a conductive member 336 that is contained in thebase member 324. The conductive member 336 can be made of any suitablematerial as described above. The conductive member 336 includes anannular-shaped surface 338 against which the tubing joint 318 can beplaced. The sensor apparatus 334 further includes a lid 340 that ispivotally attached to the base member 324. The lid 340 has a member 342that abuts against a portion of the tubing joint in a closed position.This secures the tubing joint in place for use.

[0160] As previously discussed, the sensor apparatus of the presentapplication can be used in a number of suitable applications. Forexample, the sensor apparatus can be suitably coupled to a blood circuitand used for purposes of detecting disconnection of an access device asdescribed in the present application. Another application includes themonitoring of solution compounding as described in greater detail below.In this regard, the sensor apparatus as shown in FIGS. 7A and 7B can beused in combination with or in place of the electrical coupling devicesas illustrated in FIGS. 2A-2E and further described above. Thus, thepresent invention can be utilized to monitor one or a combination ofconditions, such as patient access and solution mixing, during use. Asapplied, the sensor apparatus can be connected to a controller or otherlike device for detection purposes. The controller can include one or anumber of different devices that are in electrical contact with thesensor apparatus in any suitable way.

[0161] In another embodiment, the sensor apparatus can include a singlepiece part that is made from the conductive polymer material. The singlepiece part can be made in any suitable way such as through injectionmolding as described above. A number of different and suitable shapesand sizes can be formed. One such example illustrative of the presentinvention of a single piece part conductive electrode 344 is shown inFIGS. 8A and 8B.

[0162] In general, the conductive polymer electrode 344 is configured asa coupler that can join tubing to form a tubing joint through whichfluid can flow as shown in FIGS. 8A and 8B. The conductive polymerelectrode 344 includes a base member 346 that has an annular opening 348extending therethrough. A tube member 350 can be attached to the ends351 of the annular opening 348 such that the tubing joint can be formedas described above. The base member 346 includes a stem portion 352 thatextends from a portion of a surface 354 of the base member 346. This canbe used to mount or attach the conductive polymer electrode 344 to acontrol panel or other suitable component, such as a hemodialysismachine as described above. The stem portion 352 defines anannular-shaped channel 356 that ends from the surface 354 of the basemember 346. Within the annular-shaped channels, an inner annular-shapedchannel 360 is also provided that extends from the surface 354 of thebase 346, as shown in FIG. 8B. The stem portion can be utilized toprovide a pathway through which the electrode can be in electricalcontact with one or more other devices, such as a controller, in anysuitable way. The base member further includes a top member 362 thatextends from a portion of the surface 354 of the base member 346. Thetop member 362 can be used to secure the stem portion 352 of the basemember 346 in place for use and/or to remove the electrode after use.

[0163] As shown in FIGS. 8A and 8B, the conductive polymer electrode 344includes a member 366 that extends from an inner surface of the annularopening 348. The member 366 acts as a stop against which the tubing canbe placed to form the tubing joint. The member 366 has agenerally-cylindrical shape with an opening 368 through which fluid canflow.

[0164] As previously discussed, the conductive polymer material of thepresent invention can be utilized in a number of different applications.In an embodiment, the conductive polymer material can be utilized tomonitor patient access conditions, such as to detect disconnection of anaccess device that is inserted in a patient through which fluid flowsduring medical therapy. Preferably, the disconnection detectionapplication is applied during dialysis therapy, such as duringhemodialysis therapy.

[0165] As applied to dialysis applications, the conductive polymer canbe formed into an electrode and attached to a dialysis blood circuit inany suitable manner. As shown in FIGS. 1A and 2A and further describedabove, at least one of the sensors can include an electrode made withthe conductive polymer material of the present invention. The sensors 22and 24 are in electrical contact with a controller 29 and thus theconductive polymer electrode can be utilized for detection, monitoringand control purposes related to dialysis therapy as described above. Asshown in FIGS. 4A and 4B and described in the present application, thesensors 198 can be attached directly to the hemodialysis machine whereinat least one of the sensors includes a conductive polymer electrodeaccording to an embodiment of the present invention. The conductivepolymer sensor can be configured in any suitable way, such as thecoupler and hub design (See, FIGS. 5A, 5B, 7A and 7B), the single-piecepart design (See, FIGS. 8A and 8B) and dialyzer header design (See,FIGS. 8A and 8B) as described above. It should be appreciated that thepresent invention contemplates the use of one or a combination ofdifferent sensors to monitor medical therapy, such as patient access andsolution mixing conditions.

[0166] In an embodiment, the conductive polymer material of the presentinvention can be utilized for monitoring the mixing of solutions to forma mixed solution, such as a mixed solution used during medical therapy.One type of application illustrative of the present invention for suchmonitoring purposes is during dialysis therapy, particularly duringperitoneal dialysis. In general, the conductive polymer material can beformed into an electrode or other sensing device that can effectivelydetect changes in conductivity associated with a dialysis solution thatis administered to the patient during peritoneal dialysis.

[0167] The dialysis solution can be formed from a number of solutioncomponents that are mixed to form a mixed dialysis solution prior toadministration. The dialysis solution components can have varying pHlevels, such as ranging from about 1.8 to about 9.2. Once mixed, the pHof the mixed dialysis solution should be at a physiologically acceptablelevel, such as ranging from about 6.8 to about 7.5, prior to use. The pHlevel can be monitored in relation to changes in the conductivity levelof the dialysis solution. In this regard, the conductive polymer of thepresent invention can be utilized to detect changes in conductivitylevel and thus can be utilized to determine whether the solutioncomponents are properly mixed to form the mixed dialysis solution at anacceptable pH level prior to use. A general description of peritonealdialysis is provided below and is illustrative of the present invention.

[0168] Peritoneal dialysis utilizes a sterile dialysis solution, whichis infused into a patient's peritoneal cavity and into contact with thepatient's peritoneal membrane. Waste, toxins and excess water pass fromthe patient's bloodstream through the peritoneal membrane and into thedialysis solution. The transfer of waste, toxins, and excess water fromthe bloodstream into the dialysis solution occurs due to diffusion andosmosis during a dwell period as an osmotic agent in the dialysissolution creates an osmotic gradient across the membrane. The spentsolution is later drained from the patient's peritoneal cavity to removethe waste, toxins and excess water from the patient.

[0169] There are various types of peritoneal dialysis therapies,including continuous ambulatory peritoneal dialysis (“CAPD”) andautomated peritoneal dialysis. CAPD is a manual dialysis treatment, inwhich the patient connects the catheter to a bag of fresh dialysissolution and manually infuses fresh dialysis solution through thecatheter or other suitable access device and into the patient'speritoneal cavity. The patient disconnects the catheter from the freshdialysis solution bag and allows the solution to dwell within the cavityto transfer waste, toxins and excess water from the patient'sbloodstream to the dialysis solution. After a dwell period, the patientdrains the spent dialysis solution and then repeats the manual dialysisprocedure. Tubing sets with “Y” connectors for the solution and drainbags are available that can reduce the number of connections the patientmust make. The tubing sets can include pre-attached bags including, forexample, an empty bag and a bag filled with dialysis solution.

[0170] In CAPD, the patient performs several drain, fill, and dwellcycles during the day, for example, about four times per day. Eachtreatment cycle, which includes a drain, fill and dwell, takes aboutfour hours.

[0171] Automated peritoneal dialysis is similar to continuous ambulatoryperitoneal dialysis in that the dialysis treatment includes a drain,fill, and dwell cycle. However, a dialysis machine automaticallyperforms three or more cycles of peritoneal dialysis treatment,typically overnight while the patient sleeps.

[0172] With automated peritoneal dialysis, an automated dialysis machinefluidly connects to an implanted catheter. The automated dialysismachine also fluidly connects to a source or bag of fresh dialysissolution and to a fluid drain. The dialysis machine pumps spent dialysissolution from the peritoneal cavity, through the catheter, to the drain.The dialysis machine then pumps fresh dialysis solution from the source,through the catheter, and into the patient's peritoneal cavity. Theautomated machine allows the dialysis solution to dwell within thecavity so that the transfer of waste, toxins and excess water from thepatient's bloodstream to the dialysis solution can take place. Acomputer controls the automated dialysis machine so that the dialysistreatment occurs automatically when the patient is connected to thedialysis machine, for example, when the patient sleeps. That is, thedialysis system automatically and sequentially pumps fluid into theperitoneal cavity, allows for dwell, pumps fluid out of the peritonealcavity, and repeats the procedure.

[0173] Several drain, fill, and dwell cycles will occur during thetreatment. Also, a final volume “last fill” is typically used at the endof the automated dialysis treatment, which remains in the peritonealcavity of the patient when the patient disconnects from the dialysismachine for the day. Automated peritoneal dialysis frees the patientfrom having to manually perform the drain, dwell, and fill steps duringthe day.

[0174] In general, the dialysis solution includes an osmotic agent, suchas dextrose or other suitable constituent in any suitable amount, suchas from about 1.5% to about 4.25% by weight. The dialysis solutionfurther includes one or more electrolytes, such as sodium, calcium,potassium, magnesium chloride and/or the like in any suitable amount.The dialysis solution may also include other constituents, such asbuffers including lactate and bicarbonate, or the like, and otherconstituents, such as stabilizers. The dialysis solution can be madefrom multiple solution components that can vary in the amounts and typesof constituents thereof and have varying pH levels.

[0175] A variety of different and suitable types of multi-part dialysissolutions can be utilized. For example, a multi-part bicarbonate-basedsolution can be found in U.S. patent application Ser. No. 09/955,248,entitled BIOCHEMICALLY BALANCED PERITONEAL DIALYSIS SOLUTIONS, filed onSep. 17, 2001, the disclosure of which is incorporated herein byreference. An example of a multi-part lactate-based solution can befound in U.S. patent application Ser. No. 10/628,065, entitled DIALYSISSOLUTIONS WITH REDUCED LEVELS OF GLUCOSE DEGRADATION PRODUCTS, filed onJul. 25, 2003 the disclosure of which is herein incorporated byreference.

[0176] Another example of a bicarbonate-based solution can be found inU.S. patent application Ser. No. 10/044,234, entitled BICARBONATE-BASEDSOLUTIONS FOR DIALYSIS THERAPIES, filed on Jan. 11, 2002 and as furtherdisclosed in U.S. Pat. No. 6,309,673, the disclosures of which areherein incorporated by reference. The bicarbonate-based solution can bemade from solution components that have varying pH conditions, such asunder moderate and extreme pH conditions. In an embodiment, the solutioncomponents can vary in pH from between about 1.0 to about 10.0. Oncemixed, the desired pH of the mixed solution is a physiologicalacceptable level, such as between about 6.5 to about 7.6 (i.e., close tothe pH of blood).

[0177] For example, under moderate pH conditions, the bicarbonate-basedsolution can be formulated by the mixing of a bicarbonate concentratewith a pH that ranges from about 7.2 to about 7.9, preferably from about7.4 to about 7.6, and an electrolyte concentrate with a pH that rangesfrom about 3.0 to about 5.0. Under extreme pH conditions, for example,the bicarbonate concentrate has a pH that can range from about 8.6 toabout 9.5 and is mixed with an electrolyte concentrate that has a pHfrom about 1.7 to about 2.2. A variety of different and suitable acidicand/or basic agents can be utilized to adjust the pH of the bicarbonateand/or electrolyte concentrates. For example, a variety of inorganicacids and bases can be utilized, such as hydrochloric acid, sulfiricacid, nitric acid, hydrogen bromide, hydrogen iodide, sodium hydroxide,the like or combinations thereof.

[0178] The solution components, such as the electrolyte concentrate andthe dextrose concentrate, can then be mixed in the solution bag and thenadministered as a mixed solution to the patient during peritonealdialysis. An illustrated example of a multi-chamber container thatseparately contains solution components of a dialysis solution accordingto embodiment of the present invention is shown in FIG. 9.

[0179] It should be appreciated that the components of the dialysissolutions of the present invention can be housed or contained in anysuitable manner such that the dialysis solutions can be effectivelyprepared and administered. In an embodiment, the present inventionincludes a multi-part dialysis solution in which two or more parts areformulated and stored separately, and then mixed just prior to use. Avariety of containers can be used to house the various parts of thedialysis solution, such as separate containers (i.e., flasks or bags)that are connected by a suitable fluid communication mechanism.

[0180] In an embodiment, a multi-chamber container or bag can be used tohouse the separate components of the solution including, for example, adextrose concentrate and a buffer concentrate. In an embodiment, theseparate components are mixed within the multi-chamber bag prior to use,such as applied during peritoneal dialysis.

[0181]FIG. 9 illustrates a suitable container for storing, formulating,mixing and administering a dialysis solution, such as during continuousambulatory peritoneal dialysis, according to an embodiment of thepresent invention. The multi-chamber bag 380 has a first chamber 382 anda second chamber 384. The interior of the container is divided by a heatseal 386 into the two chambers. It should be appreciated that thecontainer can be divided into separate chambers by any suitable seal.

[0182] In an embodiment, the container can be divided into separatechambers, such as two or more chambers, by a peel seal. With the use ofa peel seal, a frangible connector or other suitable type of connectorwould not be required to mix the solution components within themulti-chamber bag. An example of a multi-chamber solution bag thatincludes a peel seal is disclosed in U.S. Pat. No. 6,319,243, thedisclosure of which is herein incorporated by reference. As shown inFIG. 10, a container 388 includes at least three chambers 390, 392 and394. The chambers 390, 392 and 394 are designed for the separate storageof liquids and/or solutions, that can be mixed within the container toform a mixed solution ready-for-use. It should be appreciated that moreor less than three chambers can be utilized.

[0183] The peelable seals 396 and 398 are provided between the chambers390, 392 and 394, respectively. Examples of peelable seals can be foundin U.S. patent application Ser. No. 08/033,233 filed on Mar. 16, 1993entitled “PEELABLE SEAL AND CONTAINER HAVING SAME”, the disclosure ofwhich is herein incorporated by reference. The peelable seals allow forthe selective opening of the chambers to allow for the selective mixingof the liquids contained therein.

[0184] The container 388 can also include tubular ports, such as tubularports 400, 402 and 404 as shown in FIG. 10. The tubular ports aremounted to the container so as to allow fluid communication with thecontainer and specifically with chambers 390, 392 and 394. To this end,the tubular ports 400, 402 and 404 can include a membrane that ispierced, for example, by a cannula or a spike or an administration setfor delivery of the contents of the container to the patient. It shouldbe appreciated that more or less than three ports can be utilized.

[0185] As shown in FIG. 9, the multi-chamber container 380 has afrangible connector 406 to sealingly couple the first chamber 382 to thesecond chamber 384 instead of a peelable seal. To mix the solutionwithin the multi-chamber bag 380, the frangible connector 406 is broken.

[0186] The first container or chamber 382 includes two port tubes 408 ofsuitable sizes and lengths. It should be appreciated that more or lessthan two port tubes may be used. One of the port tubes, for example, canbe utilized to add other constituents to the first chamber 382 duringformulation of the solution of the present invention, if necessary. Theremaining port tube, for example, can be utilized to adaptedly couplethe first chamber 382 to the patient via a patient's administration line(not shown), be used to add additional other constituents or the like.The second container or chamber 384 has a single port tube 410 extendingthere from. In an embodiment, the port tube 410 is connected to apatient's administration line through which a solution can flow to thepatient once the solution is mixed as described below.

[0187] In an embodiment, the transfer of product within themulti-chamber bag 380 can be initiated from the first chamber 382 to thesecond chamber 384 such that the components of each chamber can beproperly mixed to form the dialysis solution of the present invention.In an embodiment, a dextrose concentrate 412 is contained in the firstchamber 382 and a buffer concentrate 414 is contained in the secondchamber 384. It should be appreciated that any suitable type or numberof solution components can be separated with a multi-chamber bag andthen mixed to form a mixed solution prior to administration to thepatient. Illustrative examples of peritoneal dialysis solutions includethose described in U.S. patent application Ser. Nos. 09/955,298 and10/628,065 and U.S. Pat. No. 6,309,673 as described above.

[0188] The first chamber 382 is smaller in volume than the secondchamber 384 such that the components of each chamber can be properlymixed once the transfer from the first chamber to the second chamber hasoccurred. Thus, the multi-chamber bag 380 can house at least twosolution component parts that after mixture will result in aready-to-use dialysis solution. An example of the multi-chambercontainer is set forth in U.S. Pat. No. 5,431,496, the disclosure ofwhich is incorporated herein by reference. The multi-chamber bag can bemade from a gas permeable material, such as polypropylene, polyvinylchloride or the like.

[0189] It should be appreciated that the multi-chamber bag can bemanufactured from a variety of different and suitable materials andconfigured in a number of suitable ways such that the dialysis solutionsof the present invention can be effectively formulated and administeredto the patient during medical therapy in any suitable manner. Forexample, the first chamber can be larger in volume than the secondchamber and further adapted such that the dialysis solution of thepresent invention can be readily and effectively made and administeredto the patient.

[0190] In an embodiment, the dialysis solution is contained andadministered from a multi-chamber solution bag during peritonealdialysis, such as during CAPD. The solution bag can include multiplechambers that each contain separate components of the dialysis solutionprior to mixing as discussed above. This may be necessary to maintainseparation of the non-compatible solution components prior to mixing forpurposes of stability, sterility, effectiveness or the like associatedwith the dialysis solution prior to use.

[0191] In another embodiment, the solution components can be preparedand stored in separate containers and then mixed via an admix deviceprior to use, such as applied during automated peritoneal dialysis. Asshown in FIG. 11, a first solution component, such as a dextroseconcentrate 416 and a second solution component, such as a bufferconcentrate 420 are stored in the respective separate containers 422 and424 or bags which are fluidly connected to an admix device 426 suitablefor use during automated peritoneal dialysis, an example of whichincludes ADMIX HOMECHOICE by BAXTER INTERNATIONAL, INC. In addition tothe first and second components, a first bag 428 and last bag 430 filledwith a suitable solution can also be used during dialysis therapy asgenerally known.

[0192] In an embodiment, an effective amount of the first solutioncomponent 416 and the second solution component 420 are drawn from eachrespective container and into a heater bag 432 where the solutioncomponents (e.g., dextrose and buffer concentrates) can be mixed andheated prior to infuision into a patient 434 during dialysis therapy. Asfurther shown in FIG. 11, a drain line 436 is coupled to the admixdevice 426 from which waste fluids can be removed from the patientduring therapy.

[0193] According to an embodiment of the present invention, theconductive polymer material can be used as a sensor to monitor solutioncompounding, such as during peritoneal dialysis. For example, theconductive polymer sensor 438 can be attached to a tube 440 throughwhich the mixed dialysis solution flows to the patient from themulti-chamber solution bag 380 as shown in FIG. 9. The conductivepolymer sensor 438 is in electric contact with a controller 442 or otherlike device such that a change in conductivity of the mixed dialysissolution that is fed to the patient can be monitored. Based on theconductivity level, one can monitor the pH level of the mixed solutionto determine whether the solution components (e.g., dextrose concentrateand buffer concentrate) have been properly and sufficiently mixed toform the dialysis solution prior to use. If the dialysis solution is notproperly mixed, the conductivity level will exist above or below abaseline conductivity level that is generally associated with a desiredpH level of a dialysis solution that is ready-for-use. As previouslydiscussed, the desired pH of the mixed dialysis solution is maintainedat a physiological acceptable level, such as between about 6.5 to about7.6 prior to use. Based on this information, adjustments can be made tothe process such that the solution chemistry of the dialysis solution ismodified for proper use. This can facilitate the safe and effective useof the solution during use, such as during dialysis therapy.

[0194] As shown in FIG. 11, the conductive polymer sensor 444 of thepresent invention can be applied during automated peritoneal dialysis.More specifically, the conductive polymer sensor 444 of the presentinvention can be attached to the tube member 446 through which adialysis solution flows to the patient. The dialysis solution is aproduct of the mixing of solution components that are stored in separatesolution bags as previously discussed. The conductive polymer sensor 444can be attached to a controller 448 or other like device in electricalcontact such that the conductivity level and thus the pH level of thesolution that is administered to the patient can be monitored aspreviously discussed. Optionally, at least one additional conductivepolymer sensor 450 in an embodiment can also be utilized as shown inFIG. 11. In this regard, the additional sensor(s) can be utilized tomonitor the conductivity level of the solution components prior tomixing. This can be utilized to evaluate whether the solution componentsare maintained at desired pH levels based on a conductivity measurementas discussed above.

[0195] It should be understood that various changes and modifications tothe presently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present invention andwithout diminishing its intended advantages. It is therefore intendedthat such changes and modifications be covered by the appended claims.

The invention is claimed as follows:
 1. A conductive material comprisinga conductive polymer component electrically sensitive to a conditionchange when in contact with a solution used during dialysis therapy. 2.The conductive material of claim 1, wherein the conductive polymercomponent includes a polymer matrix and a conductive component that isincorporated in the polymer matrix.
 3. The conductive material of claim2, wherein the polymer matrix is selected from the group consisting ofpolyvinyl chloride, acrylonitrile butadiene styrene, polycarbonate,acrylic, a cyclo olefin copolymer, a cyclo olefin copolymer blend, ametallocene-based polyethylene and mixtures thereof.
 4. The conductivematerial of claim 2, wherein the conductive component is selected fromthe group consisting of stainless steel, fillers, carbon black, fibersthereof and mixtures thereof.
 5. The conductive material of claim 2,wherein the conductive component includes greater than about 10% byweight of the conductive material.
 6. The conductive material of claim2, wherein the conductive component is uniformly dispersed throughoutthe polymer matrix.
 7. The conductive material of claim 2, wherein theconductive component includes a conductive fiber material that has anaspect ratio ranging from about 2:1 to about 30:1.
 8. The conductivematerial of claim 1, wherein the conductive polymer component isselected from the group consisting of polyaniline, polypyrrole,polythiophene, polyethylenedioxythiophene, poly(p-phenylene vinylene)and mixtures thereof.
 9. The conductive material of claim 1, wherein thecondition change relates to a change in impedance due to patient accessdisconnection during dialysis.
 10. The conductive material of claim 1,wherein the condition change relates to a change in conductivity basedon a change in pH level of the solution administered during dialysis.11. A coupler comprising a conductive polymer material that is soconstructed and arranged to join tubing.
 12. The coupler of claim 11,wherein the conductive polymer material includes a conductive polymercomponent selected from the group consisting of polyaniline,polypyrrole, polythiophenes, polyethylenedioxythiophene,poly(p-phenylene vinylene) and mixtures thereof.
 13. The coupler ofclaim 11, wherein the conductive polymer material includes a polymermatrix and a conductive component incorporated within the polymermatrix, and wherein the polymer matrix is selected from the groupconsisting of polyvinyl chloride, acrylonitrile butadiene styrene,polycarbonate, acrylic, a cyclo olefin copolymer, a cyclo olefincopolymer blend, a metallocene-based polyethylene and mixtures thereof.14. The coupler of claim 13, wherein the conductive component isselected from the group consisting of stainless steel, fillers, carbonblack, fibers thereof and mixtures thereof.
 15. The coupler of claim 11,wherein the coupler has a generally cylindrical shape with a firstopening and a second opening through which tubing can be joined.
 16. Thecoupler of claim 15, wherein the coupler includes an extrudable product.17. The coupler of claim 15, wherein the coupler includes a member thatextends from at least a portion of an inner surface of the couplerallowing a length of a tubing joint that is formed with the coupler andtubing to be pre-set.
 18. The coupler of claim 17, wherein the couplerincludes an injection moldable product.
 19. A sensor apparatuscomprising an electrode including a conductive polymer material.
 20. Thesensor apparatus of claim 19, wherein the conductive polymer materialincludes a polymer matrix and a conductive component wherein theconductive component is incorporated in the polymer matrix.
 21. Thesensor apparatus of claim 20, wherein the polymer matrix is selectedfrom the group consisting of polyvinyl chloride, acrylonitrile butadienestyrene, polycarbonate, acrylic, a cyclo olefin copolymer, a cycloolefin copolymer blend, a metallocene-based polyethylene and mixturesthereof.
 22. The sensor apparatus of claim 21, wherein the conductivecomponent is selected from the group consisting of stainless steel,fillers, carbon black, fibers thereof and mixtures thereof.
 23. Thesensor apparatus of claim 19, wherein the conductive polymer materialincludes a conductive polymer component selected from the groupconsisting of polyaniline, polypyrrole, polythiophene,polyethylenedioxythiophene, poly(p-phenylene vinylene) and mixturesthereof.
 24. The sensor apparatus of claim 19, wherein the electrode isattached to a tube member through which fluid flows.
 25. The sensorapparatus of claim 19, wherein the tube member is selected from thegroup consisting of polyvinyl chloride, a non-polyvinyl chloridematerial and combinations thereof.
 26. The sensor apparatus of claim 25,wherein the tube member and the electrode are attached via an attachmentmechanism selected from the group consisting of solvent bonding,heating, laser welding, and radio frequency sealing.
 27. The sensorapparatus of claim 19, wherein the electrode and at least a portion ofthe tube member attached to the electrode are secured to a device thathas a hub design.
 28. The sensor apparatus of claim 27, wherein the hubdesign includes a housing within which the electrode can be secured. 29.The sensor apparatus of claim 27, wherein the hub design includes a basemember against which the electrode can be secured.
 30. The sensorapparatus of claim 19 further comprising a controller in electricalcontact with the electrode allowing detection of a condition changeselected from the group consisting of detection of a change in impedanceas the fluid flows through the tube member, detection of a change inconductivity based on a change in pH of the fluid as the fluid flowsthrough the tube member, and combinations thereof.
 31. The sensorapparatus of claim 19, wherein the electrode is formed into a dialyzerheader.
 32. An apparatus for detecting dislodgment of an access deviceinserted into a patient during medical therapy, the apparatuscomprising: a blood circuit connecting the patient to an extracorporealblood system wherein the blood circuit includes a blood tubing sethaving a first tube member connected to a first access device and asecond tube member connected to a second access device and wherein thefirst access device and the second access device are each insertablewithin the patient such that blood flows between the patient and theextracorporeal blood system via the blood circuit; a first electrode anda second electrode in fluid contact with the blood and spaced apart fromthe first access device and the second access device, respectively,wherein at least one of the first electrode and the second electrodeincludes a conductive polymer material; and a controller in electricalcontact with each of the first electrode and the second electrodewherein the apparatus is capable of detecting a change in impedance inresponse to dislodgment of at least one of the first access device andthe second access device.
 33. The apparatus of claim 32, furthercomprising at least one additional electrode.
 34. The apparatus of claim32, wherein the conductive polymer material includes a polymer matrixand a conductive component that is incorporated in the polymer matrix.35. The apparatus of claim 34, wherein the polymer matrix is selectedfrom the group consisting of polyvinyl chloride, acrylonitrile butadienestyrene, polycarbonate, acrylic, a cyclo olefin copolymer, a cycloolefin copolymer blend, a metallocene-based polyethylene and mixturesthereof.
 36. The apparatus of claim 34, wherein the conductive componentis selected from the group consisting of stainless steel, fillers,carbon black, fibers thereof, and mixtures thereof.
 37. The apparatus ofclaim 32, wherein the medical therapy includes dialysis treatmentselected from the group consisting of hemodialysis, hemodiafiltration,hemofiltration, continuous renal replacement therapy and homehemodialysis.
 38. The apparatus of claim 32, wherein the conductivepolymer material includes a conductive polymer component selected fromthe group consisting of polyaniline, polypyrrole, polythiophene,polyethylenedioxythiophene, poly(p-phenylene vinylene) and mixturesthereof.
 39. An apparatus for monitoring delivery of a solution to apatient via an access device insertable within the patient duringmedical therapy, the apparatus comprising: a tube member connecting thepatient to a fluid system from which the solution flows into the patientvia the access device; an electrode connected to the tube member,wherein the electrode includes a conductive polymer material; and acontroller in electrical contact with the electrode allowing detectionof a change in conductivity associated with the solution.
 40. Theapparatus of claim 39, wherein the conductive polymer material includesa polymer matrix and a conductive component that is incorporated in thepolymer matrix.
 41. The apparatus of claim 40, wherein the polymermatrix is selected from the group consisting of polyvinyl chloride,acrylonitrile butadiene styrene, polycarbonate, acrylic, a cyclo olefincopolymer, a cyclo olefin copolymer blend, a metallocene-basedpolyethylene and mixtures thereof.
 42. The apparatus of claim 40,wherein the conductive component is selected from the group consistingof stainless steel, fillers, carbon black, fibers thereof and mixturesthereof.
 43. The apparatus of claim 39, wherein the fluid systemincludes a plurality of solution components that are mixed to form thesolution.
 44. The apparatus of claim 43, wherein the detection of thechange in conductivity is based on a change in pH associated with thesolution.
 45. The apparatus of claim 44, wherein the solution componentshave a varying pH level.
 46. The apparatus of claim 45, wherein thesolution components have a pH that ranges from about 1.8 to about 9.2.47. The apparatus of claim 45, wherein the solution is monitored todetermine whether the pH level of the solution is maintained at aphysiological acceptable level after mixing of the solution componentsand prior to use as a dialysis solution.
 48. The apparatus of claim 47,further comprising one or more additional electrodes for monitoringpatient access conditions during dialysis therapy.
 49. The apparatus ofclaim 43, wherein the solution components are mixed within amultiple-chamber solution bag to form a dialysis solution.
 50. Theapparatus of claim 43, wherein the solution components are separatelycontained in a respective solution bag prior to mixing to form adialysis solution.
 51. The apparatus of claim 39, wherein the conductivepolymer material includes a conductive polymer component selected fromthe group consisting of polyaniline, polypyrrole, polythiophene,polyethlenedioxythiophene, poly(p-phenylene vinylene) and mixturesthereof.
 52. A system for detecting dislodgment of an access deviceinserted into a patient during medical therapy, the system comprising: ablood circuit connecting the patient to an extracorporeal blood systemwherein the blood circuit includes a blood tubing set having a firsttube member connected to a first access device and a second tube memberconnected to a second access device and wherein the first access deviceand the second access device are each insertable within the patient suchthat blood flows between the patient and the extracorporeal blood systemvia the blood circuit; a first electrode and a second electrode in fluidcontact with the blood and spaced apart from the first access device andthe second access device, respectively, wherein at least one of thefirst electrode and the second electrode includes a conductive polymermaterial; and a controller in electrical contact with each of the firstelectrode and the second electrode capable of detecting a change inimpedance in response to dislodgment of at least one of the first accessdevice and the second access device.
 53. The system of claim 52 furthercomprising at least one additional electrode.
 54. The system of claim 52wherein the conductive polymer material includes a polymer matrix and aconductive component that is incorporated in the polymer matrix.
 55. Thesystem of claim 54, wherein the polymer matrix is selected from thegroup consisting of polyvinyl chloride, acrylonitrile butadiene styrene,polycarbonate, acrylic, a cyclo olefin copolymer, a cyclo olefincopolymer blend, a metallocene-based polyethylene and mixtures thereof.56. The system of claim 54, wherein the conductive component is selectedfrom the group consisting of stainless steel, fillers, carbon black,fibers thereof and mixtures thereof.
 57. The sensor apparatus of claim52, wherein the conductive polymer material includes a conductivepolymer component selected from the group consisting of polyaniline,polypyrrole, polythiophene, polyethylenedioxythiophene, poly(p-phenylenevinylene)s and mixtures thereof.
 58. The system of claim 57, wherein themedical therapy includes dialysis treatment selected from the groupconsisting of hemodialysis, hemodiafiltration, hemofiltration,continuous renal replacement therapy and home hemodialysis.
 59. A systemfor monitoring delivery of a solution to a patient via an access deviceinsertable within the patient during medical therapy, the systemcomprising: a tube member connecting the patient to a fluid system fromwhich the solution flows into the patient via the access device; anelectrode connected to the tube member, wherein the electrode includes aconductive polymer material; and a controller in electrical contact withthe electrode allowing detection of a change in conductivity associatedwith the solution.
 60. The system of claim 59, wherein the conductivepolymer material includes a polymer matrix and a conductive componentthat is incorporated in the polymer matrix.
 61. The system of claim 60,wherein the polymer matrix is selected from the group consisting ofpolyvinyl chloride, acrylonitrile butadiene styrene, polycarbonate,acrylic, a cyclo olefin copolymer, a cyclo olefin copolymer blend, ametallocene-based polyethylene, and mixtures thereof.
 62. The system ofclaim 60, wherein the conductive component is selected from the groupconsisting of stainless steel, fillers, carbon black, fibers thereof andmixtures thereof.
 63. The system of claim 59, wherein the conductivepolymer material includes a conductive polymer component selected fromthe group consisting of polyaniline, polypyrrole, polythiophene,polyethylenedioxythiophene, poly(p-phenylene vinylene) and mixturesthereof.
 64. The system of claim 63, wherein the fluid system includes aplurality of solution components that are mixed to form the solution.65. The system of claim 64, wherein the solution components have avarying pH level.
 66. The system of claim 65, wherein a pH of thesolution components can vary between about 1.8 to about 9.2.
 67. Thesystem of claim 65, wherein the change in conductivity is based on achange in a pH of the solution.
 68. The system of claim 67, wherein thechange in the pH is monitored to determine whether the pH of thesolution is maintained at physiological acceptable level prior to use.69. The system of claim 66, further comprising one or more additionalelectrodes for monitoring patient access conditions based on a change inimpedance in response to dislodgment of the access device.
 70. Thesystem of claim 59, wherein the solution is selected from the groupconsisting of a dialysis solution, a peritoneal dialysis solution, anutritional solution, a blood solution, an intravenous solution, andcombinations thereof.
 71. A method of detecting dislodgment of an accessdevice during dialysis, the method comprising: connecting a patient to ablood circuit having a pair of electrodes each coupled to a bloodcircuit in fluid contact with blood that flows through the blood circuitwherein at least one of the electrodes includes a conductive polymermaterial; passing an electrical signal through the blood via the pair ofelectrodes thereby defining a loop along which an impedance can bemeasured; and detecting a disconnection between the patient and theblood circuit in response to a change in the impedance.
 72. The methodof claim 71, wherein the conductive polymer material includes a polymermatrix and a conductive component incorporated within the polymermatrix.
 73. The method of claim 72, wherein the polymer matrix isselected from the group consisting of polyvinyl chloride, acrylonitrilebutadiene styrene, polycarbonate, acrylic, a cyclo olefin copolymer, acyclo olefin copolymer blend, a metallocene-based polyethylene andcombinations thereof.
 74. The method of claim 71, wherein the conductivecomponent is selected from the group consisting of stainless steel,fillers, carbon black, fibers thereof and mixtures thereof.
 75. Themethod of claim 71, wherein the conductive polymer material includes aconductive polymer component selected from the group consisting ofpolyaniline, polypyrrole, polythiophene, polyethylenedioxythiophene,poly(p-phenylene vinylene)s and mixtures thereof.
 76. A method ofmonitoring delivery of a solution to a patient during medical therapy,the method comprising: connecting a patient to a tube member throughwhich the solution can flow to the patient via an access device whereinthe tube member has an electrode attached thereto, the electrodeincluding a conductive polymer material; passing an electrical signalinto the solution via the electrode thereby allowing a conductivityassociated with the solution to be measured; and detecting a change inconductivity based on a change in pH of the solution.
 77. The method ofclaim 76, wherein the conductive polymer material includes a polymermatrix and a conductive component incorporated within the polymermatrix.
 78. The method of claim 77, wherein the polymer matrix isselected from the group consisting of polyvinyl chloride, acrylonitrilebutadiene styrene, polycarbonate, acrylic, a cyclo olefin copolymer, acyclo olefin copolymer blend, a metallocene-based polyethylene andcombinations thereof.
 79. The method of claim 77, wherein the conductivecomponent is selected from the group consisting of stainless steel,fillers, carbon black, fibers thereof and mixtures thereof.
 80. Themethod of claim 76, wherein the conductive polymer material includes aconductive polymer component selected from the group consisting ofpolyaniline, polypyrrole, polythiophene, polyethylenedioxythiophene,poly(p-phenylene vinylene) and mixtures thereof.
 81. The method of claim76, wherein the pH of the solution is monitored to determine whether thepH is maintained at a physiological acceptable level prior to use. 82.The method of claim 76, wherein the solution is derived from a mixtureof solution components that have a pH ranging from about 1.8 to about9.2.
 83. The method of claim 76, further comprising one or moreadditional electrodes that are connected to the tube member such that achange in impedance based on dislodgement of the access device can bemonitored.